The difference between a PLA and a PAL is:

• The PLA has a programmable OR plane and a programmable AND plane, while the PAL only has a programmable AND plane.
• The PAL has a programmable OR plane and a programmable AND plane, while the PLA only has a programmable AND plane.
• The PAL has more possible product terms than the PLA.
• PALs and PLAs are the same thing.