Copyleft[0] accounts for a significant but minority fraction of free software. The GPL is a Copyleft licesense, but the MIT and Apache licenses (which together might account for a majority of free software) are not. Copyleft refers to the restriction that
derivative works also be subject to the same Copyleft terms; it's the "infectious" nature of the license.
Having any license requirements at all, e.g. attribution, inclusion of license alongside distributed copies, etc. does not make the license Copyleft.
0. https://en.wikipedia.org/wiki/Copyleft