The term 'Computer Buff' refers to someone who is knowledgeable and experienced in the use of computers. The two crossword solutions for this term are 'HACKER' (6 letters) and 'USER' (4 letters). A HACKER is someone who uses their technical knowledge to gain unauthorized access to computer systems, while a USER is someone who uses a computer system for its intended purpose. Both hackers and users have a deep understanding of computers and technology, making them computer buffs.