One could find cello string at many musical stores or even online on ebay, amazon, and Craigslist. Be careful when buying cello strings because the cello uses different strings. It would be a shame to buy the string that was not needed.
The cello is one of the 4 members of the string orchestra family. If you are talking about the full string family, it is viola, cello, bass, violin, piano, and guitar.
a violin, viola and a cello or two violins and a cello
Typically a string quartet is two violins, one viola, one cello.
There are many websites or shops out there, but I only know one website, Ebay.
A string quartet
A string
The classical string quartet has a first and second violin, a viola and a cello. It was formalized by Franz Josef Haydn and perfected by him and Mozart. Nearly every classical composer since their time has written at least one string quartet.
1st violin 2nd violin Viola Cello
Typically a string quartet is two violins, one viola, one cello.
String orchestra instrumentation is 1st violin, 2nd violin, viola, cello, bass. Violincello or "cello" is a member of the violin family, as are the others listed. Many prominent composers wrote works for string orchestra. One is Tchaikovsky's "Serenade for Strings." Besides- there's always room for cello :)
Cello. All the way.
Only a 5-string or 6-string cello will have a low F string. Regular 4-string cellos are tuned C-G-D-A (low to high, in fifths). A 6 string cello adds a low F, and a high E. A 5-string cello adds EITHER a low F OR a high E.