Construction
Mike Turner explains
the construction of the viola: 
and the
differences between a viola and a violin: 
He also discusses
the character of the instrument: 
There
are normally four strings on a viola, tuned to C3, G3, D4, A4
Scroll
= curved end of the viola
Peg = device for tuning strings (by altering their tension)
Peg box = the frame that holds the pegs
Nut = the ridge on the edge of the peg box that supports the strings
Neck = the extension from the body of the viola that supports
the fingerboard
Fingerboard = the wooden surface against which the fingers are pressed
f-hole = openings in the body of the viola from which the sound
emerges
Bridge = a shaped piece of thin wood supporting the strings and through
which sound is transmitted to the body
Tailpiece = anchors the strings
Chin rest = shaped wooden rest
End pin = attaches tailpiece to body of instrument
Tip =
the end point of the bow
Hairs = the stretched horsehair (or other material) which normally
makes contact with the strings
Wood = flexible, and usually supports the hairs
Frog = the heel of the bow