Definition - What does Bread-and-Butter Application mean?
A bread-and-butter application is a slang term for essential programs without which a business cannot function. Bread-and-butter programs are usually given the highest priority for maintenance and security. The term bread and butter implies that the company needs these programs in order to put food on the table (that is, make money).
Techopedia explains Bread-and-Butter Application
Bread-and-butter applications include resource management software, warehousing software, sales software and other systems that can seriously hurt a business if they go down. IT managers often use redundant systems and backups to protect these bread-and-butter programs