Basically there are two types of paper shredders stripcut paper shredders and crosscut paper shredders.  Each produces a different size shred, so choosing one over the other depends on the degree of security a company is seeking.

Crosscut Paper Shredders

Shreds documents in 2 directions, for added security.

Smaller shreds take up less space, allowing you to empty the bin less frequently.

US Department of Defense micro-cut paper shredders turn documents into tiny particles measuring 1/23” x 7/16”.