Adult literacy rates, 2015 or most recent observation[1]
World illiteracy has halved between 1970 and 2015
Literacy Photo 2 (7193820110)

Literacy is popularly understood as an ability to read, write and use numeracy in at least one method of writing, an understanding reflected by mainstream dictionary and handbook definitions.[2][3] Starting in the 1980s, however, literacy researchers have maintained that defining literacy as an ability apart from any actual event of reading and writing ignores the complex ways reading and writing always happen in a specific context and in tandem with the values associated with that context.[4][5][6][7][8][9] The view that literacy always involves social and cultural elements[10][11] is reflected in UNESCO's stipulation that literacy is an "ability to identify, understand, interpret, create, communicate and compute, using printed and written materials associated with varying contexts."[12] Modern attention to literacy as a "context-dependent assemblage of social practices"[13] reflects the understanding that individuals' reading and writing practices develop and change over the lifespan[14] as their cultural, political, and historical contexts change.[15][16] For example, in Scotland, literacy has been defined as: "The ability to read, 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."[17]

Such expanded definitions have altered long-standing "rule of thumb" measures of literacy, e.g., the ability to read the newspaper, in part because the increasing involvement of computers and other digital technologies in communication necessitates additional skills (e.g. interfacing with web browsers and word processing programs; organizing and altering the configuration of files, etc.). By extension, the expansion of these necessary skill-sets became known, variously, as computer literacy, information literacy, and technological literacy.[18] Elsewhere definitions of literacy extend the original notion of "acquired ability" into concepts like "arts literacy,"[19] visual literacy (the ability to understand visual forms of communication such as body language, pictures, maps, and video), statistical literacy,[20] critical literacy,[21] media literacy, ecological literacy, disaster literacy,[22] and health literacy.[23]