What’s a small press? An independent press?

The terms small press and independent (or indie) press are sometimes used synonymously.

An independent press is any house not associated with the Big 5 conglomerates or their imprints. When the two terms are used distinct from each other, “small” indicates annual sales of under $50 million and generally fewer than ten books published a year. When used as distinct terms, the relationship is this: a small press is always independent, but an independent press is not always small.