A serial key, also recognized as a software key, is a specific software-based key for PC software. It certifies that the copy of the program is unique. Activation is now and then done offline by entering the key, or with online activation is requisite to prevent multiple people using the same key.
A product key, also known as a software key, is a specific software-based key for a computer program. It certifies that the copy of the program is original. Activation is sometimes done offline by entering the key.