A concerto has a group of soloists rather than just one.
A concerto grosso has a small group of soloists whereas a solo concerto has only one
A concertino, or small group of soloists (usually 2 violins, a harpsichord, and a cello), contrasts with the cocerto grosso, which is the whole string orchestra and its ripieno players.
A concertino is a solo group in a concerto grosso.
You are correct. This technique was used more commonly in the baroque era, employing the concept of terraced dynamics. The difference is often one instrument per part versus a full section.True (for apex