Continuo:
An accompany part that includes a bassline and harmonies, usually played on a Keyboard instrument and with other instruments including Such as a cello.
Ground bass:
A recurring bassline that stays the same throughout a piece of music even when the melody changes-pachelbels canon   http://www.youtube.com/watch?v=6wpPk8qk3uQ&feature=youtube_gdata_player Figured bass:
The numbers underneath the bassline of a piece of music that tell you what chord to play.
Concerto Grosso:
It is a particular type where you have a small group
String quartet:
2 violins a viola and a cello.
Vivaldi, Purcell and bach examples: