For private equity firms…and the Carlyle group could be different…but here is the typical structure:
The actual “private equity firm” itself is owned by the founders, managing directors and other officers of the firm. Mitt Romney is an example - he was a co-founder of Bain Capital - having come from the management consulting side of the business.. I will call this group “Management”.
Management basically is where the big money is made. If the PE firms buy company xyz - most of company xyz is actual owned by the “investors”. The investors are mostly pension funds, insurance companies, sovereign wealth funds, endowment funds, foundations (think Ford, etc). Whoever has big money - they invest in these deals. The investors generally own most of the company - but they usually do not have significant voting rights. Management gets the voting rights.
Management rarely puts actual “hard cash” when they buy company xyz . They get a stake from 10 - 50%..kind of a sweat equity….The investors put up the dough and management brings the deal, runs it, finances it, etc and gets a significant ownership stake. Management also gets: upfront fees (as high as 10%..sometimes..usually less) upon the initial acquisition, montly or quarterly management fees (kind of an oversight fee), a cut of the profits (a cut of free cash flow or something), performance fees…and upon the sale of a company - exit fees. They basically get fees coming and going. It is not actually there money they are investing…the money is is mostly the endowment fund at Harvard, Calpers, TIAA (Teachers), etc etc. If you look at the 10 or 20 large PE firms….you will find the actual investors are common institutions or state pension entities you would recognize.