Hybrid functionals represent a special category of exchange-correlation functionals, that mix some amount of Fock exchange into a density functional. This approach is inspired by the well-known Hartree–Fock (HF) method, which has an exact solution for uncorrelated systems.
For lectures, check here:
- Hybrid functionals by Henrique Miranda
Also check out the hybrids-functionals category on the VASP Wiki for a detailed overview of hybrid functionals implemented in VASP.