The cello, or violoncello, is a large string instrument with 4 strings that features a large range. Sound is usually created by drawing a bow against the strings, but the strings can sometimes also be plucked to produce notes. Its first versions came in the 1500s and it was initially called a bass violin. The invention of wire-wounded strings allowed for a richer bass sound that contributed towards the modern version of the cello. It was first only used in the Baroque period to accompany other instruments but soon it became a very popular solo instrument and today the cello has a large selection of concerti and pieces written for it. It is popular in chamber music and orchestras as the bass string. Read more here: https://en.wikipedia.org/wiki/Cello