The traditional definition of literacy is considered to be the ability to read and write, or the ability to use language to read, write, listen, and speak . In modern contexts, the word refers to reading and writing at a level adequate for communication, or at a level that lets one understand and communicate ideas in a literate society, so as to take part in that society. The United Nations Educational, Scientific and Cultural Organization (UNESCO) has drafted the following definition: "'Literacy' is the ability to identify, understand, interpret, create, communicate, compute and use printed and written materials associated with varying contexts. Literacy involves a continuum of learning to enable an individual to achieve his or her goals, to develop his or her knowledge and potential, and to participate fully in the wider society." In modern times, illiteracy is seen as a social problem to be solved through education.
See also: List of countries by literacy rate, Literacy in India and Literacy in the United States. 80% of the world population was literate in 1998 by the United Nations definition - the ability to read and write a simple sentence in any language. Using a definition of: "age 15 and over can read and write", the U.S. CIA World Factbook estimated in 2007 that the overall world literacy rate was 82%."
Literacy rates can vary widely from country to country or region to region. This often coincides with the region's wealth or urbanization, though many factors play a role, such as social customs which limit the education of females in some countries.
Many policy analysts consider literacy rates a crucial measure of a region's human capital. This claim is made on the grounds that literate people can be trained less expensively than illiterate people, generally have a higher socio-economic status and enjoy better health and employment prospects. Policy makers also argue that literacy increases job opportunities and access to higher education. In Kerala, India, for example, female and child mortality rates declined dramatically in the 1960s, when girls who were schooled according to the education reforms after 1948 began to raise families. Recent researchers argue, however, that such correlations may have more to do with the overall effects of schooling rather than literacy alone  . In addition to the potential for literacy to increase wealth, wealth may promote literacy, through cultural norms and easier access to schools and tutoring services.shut da fuck up lol
Traditional definitions of literacy consider the ability to "read, write, spell, listen, and speak." Since the 1980s, some have argued that literacy is ideological, which means that literacy always exists in a context, in tandem with the values associated with that context. Prior work viewed literacy as existing autonomously. 
Some have argued that the definition of literacy should be expanded. For example, in the United States, the National Council of Teachers of English and the International Reading Association have added "visually representing" to the traditional list of competencies. Similarly, in Scotland, literacy has been defined as: "The ability to read and write and use numeracy, to handle information, to express ideas and opinions, to make decisions and solve problems, as family members, workers, citizens and lifelong learners."
A basic literacy standard in many societies is the ability to read the newspaper. Increasingly, communication in commerce or society in general requires the ability to use computers and other digital technologies.  Since the 1990s, when the Internet came into wide use in the United States, some have asserted that the definition of literacy should include the ability to use tools such as web browsers, word processing programs, and text messages. Similar expanded skill sets have been called multimedia literacy, computer literacy, information literacy, and technacy.
"Arts literacy" programs exist in some places in the United States, Australia, Canada, and Finland.
Other genres under study by academia include critical literacy, media literacy, and health literacy With the increasing emphasis on evidence-based decision making, and the use of statistical graphics and information, statistical literacy is becoming a very important aspect of literacy in general. The International Statistical Literacy Project is dedicated to the promotion of statistical literacy among all members of society.
It is argued that literacy includes the cultural, political, and historical contexts of the community in which communication takes place.
Although the history of literacy goes back several thousand years to the invention of writing, what constitutes literacy has changed throughout history. At one time, a literate person was one who could sign his or her name. At other times, literacy was measured only by the ability to read and write Latin regardless of a person's ability to read or write his or her vernacular. Even earlier, literacy was a trade secret of professional scribes, and many historic monarchies maintained cadres of this profession, sometimes - as was the case for Imperial Aramaic - even importing them from lands where a completely alien language was spoken and written.In 12th and 13th century England, the ability to read a particular passage from the Bible entitled a common law defendant to the so-called benefit of clergy, which entitled a person to be tried before an ecclesiastical court, where sentences were more lenient, instead of a secular one, where hanging was a likely sentence. This opened the door to lay, but nonetheless literate, defendants also claiming the benefit of clergy, and - because the Biblical passage used for the literacy test was inevitably Psalm 51 - an illiterate person who had memorized the appropriate verse could also claim the benefit of clergy.
By the mid-18th century, the ability to read and comprehend translated scripture led to Wales having one of the highest literacy rates. This was the result of a Griffith Jones's system of circulating schools, which aimed to enable everyone to read the Bible in Welsh. Similarly, at least half the population of 18th century New England was literate, perhaps as a consequence of the Puritan belief in the importance of Bible reading. By the time of the American Revolution, literacy in New England is suggested to have been around 90 percent.
The ability to read did not necessarily imply the ability to write. The 1686 church law (kyrkolagen) of the Kingdom of Sweden (which at the time included all of modern Sweden, Finland, and Estonia) enforced literacy on the people and by the end of the 18th century, the ability to read was close to 100 percent. But as late as the 19th century, many Swedes, especially women, could not write.
Although the present-day concepts of literacy have much to do with the 15th century invention of the movable type printing press, it was not until the industrial revolution of the mid-19th century that paper and books became financially affordable to all classes of industrialized society. Until then, only a small percentage of the population were literate as only wealthy individuals and institutions could afford the prohibitively expensive materials. As late as 1841, 33% of all Englishmen and 44% of Englishwomen signed marriage certificates with their mark as they were unable to write (government-financed public education became available in England in 1870). Even , the dearth of cheap paper and books is a barrier to universal literacy in some less-industrialized nations.
From another perspective, the historian Harvey Graff has argued that the introduction of mass schooling was in part an effort to control the type of literacy that the working class had access to. According to Graff, literacy learning was increasing outside of formal settings (such as schools) and this uncontrolled, potentially critical reading could lead to increased radicalization of the populace. In his view, mass schooling was meant to temper and control literacy, not spread it.
Literacy has also been used as a way to sort populations and control who has access to power. Because literacy permits learning and communication that oral and sign language alone cannot, illiteracy has been enforced in some places as a way of preventing unrest or revolution. During the Civil War era in the United States, white citizens in many areas banned teaching slaves to read or write presumably understanding the power of literacy. In the years following the Civil War, the ability to read and write was used to determine whether one had the right to vote. This effectively served to prevent former slaves from joining the electorate and maintained the status quo. In 1964, educator Paulo Freire was arrested, expelled, and exiled from his native Brazil because of his work in teaching Brazilian peasants to read.
Between 1500 and 1800, the approaches to reading changed as well. Briggs and Burke (2002) give examples of five types of reading changes 
The increasing number of texts available, due to the printing press, allowed readers to compare and contrast varying opinions and accounts. Reading was not always critical: there is evidence to suggest that books were at times revered and were taken as an absolute truth.
Private reading was at times viewed dangerous. It was argued that reading acted as a tranquilliser and was especially dangerous when practised by subordinate groups such as ‘common people’ or women. At the conclusion of the sixteenth-century, and later on, unsupervised reading was considered subversive by secular and theocratic authorities.
From the early sixteenth century onwards it was viewed as especially dangerous for women to read fiction. This notion originated from men who feared fiction for its potential to evoke dangerous emotions such as love.
Creative reading is spawned by the prospect that texts can and are read in ways divergent to the author’s intentions. In a sixteenth century heresy trial an Italian miller, Menocchio, was questioned as to what books he read. The Inquisition was less concerned with what Menocchio actually read, and more in his interpretations of reading.
In the late eighteenth century a reading revolution of sorts was experienced. With a wide variety of sources available and an increasing literacy rate, books were consulted for information on specific topics. Consequently the practices of skimming, browsing and chapter hopping became prevalent.
Books changed in format to accommodate skimming and browsing. Books were broken down into chapters and further into paragraphs, with notes in the margins of the page to assist in the summarisation of sections of text. Features such as table of contents and indexes were also added to books to assist readers in locating specific information. Smaller books were introduced into the market that reflected the privatisation of reading. This shift in reading is directly associated with the rise of individualism; reflected in popular eighteenth century images of men and women reading alone, seemingly unaware of that around them.
In South Asia, attitudes toward literacy vary by social sector. Many see literacy as associated with schooling and not with everyday life, and some see greater prestige in relying on memorized texts than on being able to read. However, these ideas are slowly on the decline, as modern education diffuses into the region
In much of Africa, literacy is associated with colonialism, whereas orality is associated with native traditions.
Catherine McBride-Chang researches cross-cultural studies in literacy and finds common themes worldwide. These include lower achievement levels for boys in early years of schooling in reading, and different incidence rates of diagnosed dyslexia across different cultures and languages.
See main article: Reading education. Literacy comprises a number of subskills, including phonological awareness, decoding, fluency, comprehension, and vocabulary. Mastering each of these subskills is necessary for students to become proficient readers.
Many children experience difficulty when learning to read. Learning to read is difficult because reading requires the mastery of a code that maps human speech sounds to written symbols. Mastering this code is not a natural process, like the development of language, and therefore requires instruction. Reading can be very difficult if students do not get good instruction in this code.
Readers of alphabetic languages must understand the alphabetic principle in order to master basic reading skills. A writing system is said to be alphabetic if it uses symbols to represent individual language sounds, though the degree of correspondence between letters and sounds varies across alphabetic languages. Syllabic writing systems (such as Japanese kana) use a symbol to represent a single syllable, and logographic writing systems (such as Chinese) use a symbol to represent a morpheme.
Phonics is an instructional technique that teaches readers to attend to the letters or groups of letters that make up words. A common method of teaching phonics is synthetic phonics, in which a novice reader pronounces each individual sound and "blends" them to pronounce the whole word. Another method of instruction is embedded phonics instruction, used more often in whole language reading instruction, in which novice readers learn a little about the individual letters in words, especially the consonants and the "short vowels." Teachers provide this knowledge opportunistically, in the context of stories that feature many instances of a particular letter. Embedded instruction combines letter-sound knowledge with the use of meaningful context to read new and difficult words.