Question

difference between a church and Basilica

Answer 1

The papal or major basilicas outrank in precedence all other churches. Other rankings put the cathedral (or co-cathedral) of a bishop ahead of all other churches in the same diocese, even if they have the title of minor basilica. ... So basilicas as Christian buildings are mainly a Catholic phenomenon.

Answer 2

A church is a "house of worship," a building in which Christians gather to perform the rituals of their religion and interact with one another and hold religious functions and so on. They can be very plain, very simple.

A basilica was originally a Roman building featuring certain architectural elements that supported its use as a public, open facility for business, trading, etc. These typically —but not always— included colonnades, naves, and aisles, not unlike a modern pedestrian mall.