In the past, the standard of illiteracy was illiteracy. What is the standard of illiteracy now?

With the advent of the era of knowledge economy, illiteracy not only refers to "illiterate people", but may be caused by some kind of

In the new century, the United Nations has redefined the standard of illiteracy and divided it into three categories:

The first category, people who can't read and write, are illiterate in the traditional sense;

The second category, people who can't recognize modern social symbols (that is, maps, graphs and other commonly used charts);

The third category, people who can't learn, communicate and manage with computers.

The latter two types are considered as "functional illiteracy". Although they have received basic literacy education, they have great difficulties in the highly developed social life of modern information dissemination.