A concordance of any word is a list of sentences the word appears in, taken from authentic material – newspapers, magazines, radio programs, television programs, books, etc.
Example: A concordance of the word can might include sentences like this:
There’s a can of tuna in the cupboard. Can you help me? I’d love to come, but I don’t think I can. It’s a picture of a can-can dancer by Toulouse-Lautrec. I can’t imagine anything more ridiculous.
Concordances are used for compiling the definitions and examples that appear in many ELT dictionaries.