Permissive
Fewer restrictions on what the user can do with the software
Allows to use the software without contributing back (Can create proprietary derivative)
MIT, ISC, 2-Clause BSD : Similar Licensing
Apache, BSD 3-Clause
Copyleft
Prevents users from using the software without contributing back
GPLv2, GPLv3, AGPL
LGPL, MPL : Weak Copyleft
Dual Licensing
All code contributions must be compatible with both licenses
Usually means that the user can pick which of the two licenses they want to use