also bread-and-butter
1.
Something that is the bread and butter of a person or organization is the activity or work that provides the main part of their income.
The mobile phone business was actually his bread and butter.
N-UNCOUNT : usu with poss
2.
Bread and butter issues or matters are ones which are important to most people, because they affect them personally.
The opposition gained support by concentrating on bread-and-butter matters.
ADJ : ADJ n