What does illiteracy mean in 2 1 century?

Unesco redefined "illiteracy" in 2 1 century;

The first category is illiterate, that is, illiteracy in the traditional sense;

The second category is people who can't understand the social symbols of knowledge economy;

The third category is people who can't study, work and communicate with computers.

In order to meet the challenges of the new century and avoid becoming illiterate in the high-tech era, the key is to master learning methods and constantly update their knowledge structure.