As a vendor category, third-party data about companies and contacts for prospecting; in plain usage, insight into your own sales.
The term has two meanings. As a product category it is purchased data: firmographics, contacts, buying signals, used to find accounts a business does not have. In plain English it is intelligence about the sales a business already makes. The first cannot see your ledger; the second is built from it. When someone asks for sales intelligence, ask which they mean.
As a vendor category, purchased data about companies and contacts for finding new accounts. In plain usage, insight into the sales a company already makes, from its own ledger and activity.
A prospecting database lists 4,000 companies in a sector with contacts. It cannot say which of your 1,800 existing customers buy half of what similar customers buy.
A prospecting database bought to fix retention. It cannot see your customers.