Linked from
The 8 pages that link to Equivalence class, each with the reason it gives.
Almost everywhereRelated: Function spaces often identify functions that differ only on a null set.
ElementBroader topic: An element determines a class containing every object equivalent to it.
Partition of a setRelated: Equivalence classes are the blocks in the relation-based construction.
Quotient setBroader topic: Each such class is one element of the quotient set.