chronographic tuner Can recognize any note.
guitar tuner This tuner recognizes just the six notes of the guitar strings.
chord The combination of two or more notes.
frets The vertical metal strips on the guitar neck. see Guitar Anatomy
strings Oh come on!
bridge The thing that holds the strings on the body of the guitar. see Guitar Anatomy
nut (The person holding the guitar...just kidding) Holds the strings at the head of the guitar. see Guitar Anatomy
capo A device used to change the key while playing the same chord formation. see capo