These financial services are provided by so-called "microfinance institutions" (MFIs) or "microlenders", which are simply generic terms for the estimated 10,000 diverse entities such as commercial banks, NGOs, credit unions, finance companies etc.
While from now on I will have microcredit in mind when referring to microfinance in general, please keep in mind that microfinance services are much broader and also include insurance, deposit taking and sometimes even pensions. However, the most important element of microfinance today is still micro credit.