"Finished compost is in appearance very much like black crumbly loam.
It smells sweet like soil....
and contains all the plant foods which are necessary"
JLH Chase
British gardens have some of the most varied soil types from free-draining sandy soils to heavy clay. Compost can often help give 'body' to sandy soils to help retain moisture or increase the ability of clay-type soils to drain.
If you are interested in national soil types, Soilscapes (developed by Cranfield University) gives a fascinating view.
The essential ingredients of fertile soil
It can take anything from four weeks to two years to make good compost. It depends on how much effort is put in to get the right mix of materials and conditions.