system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: When businesses say they accept all "major" credit cards, what exactly does that mean? Is there such thing as a "minor" credit card? And if so, what are they and how do they work?
gpt
Major refers to visa/mastercard, and in most cases discover and Amex. 

As opposed to saying they take any credit card, because your sears card won't work, unless it's a visa branded one (which many store cards are going to.)

Also, for the latter half of the last century you had diners club which was mostly accepted at hospitality driven places like restaurants and hotels. 

The terminology is simply outdated but once made sense and it's carried on.