You can differentiate between daycare and a nursery school
Daycare begins from 6 weeks onward and
nursery school is for 3-5 year olds.
Daycare is watching the child, feeding him, letting him play with toys and friends in a safe and caring environment.
Nursery school is all of the above wth the added element of teaching academic concepts (pre-reading and math skills).
Daycare offers some intellectual stimmulation during circle time (show and tell, story hour, sing-a-longs).
Nursery school's focus is school readiness, preparing for entry in school.
Daycare providers are usually not licenced teachers, but may be licenced to offer childcare by the state.
Nursery school teachers usually have a degree in Early Childhood Education and are certified.
Headstart is one public program that has imporved school performance in children by getting them involved academically before kindergarten.
How about in your country? What do working parents do for childcare where you live?