The electric guitar works by having a player vibrate a string which is then amplified through the instrument's pick-up system. One way to vibrate the strings is with a pick, or plectrum, which is a small plastic device that the player uses to "attack" one or more strings at a time. When a player hits one string at a time it is called "picking." When a player hits more than one strings at a time it is called "strumming." Picking is most often used for melody and soloing lines, while strumming is most often used to sound chords.
An electric guitarist can also play the instrument with his fingers, which is called finger-picking. The player "plucks" one or more strings with his fingers and/or thumb causing the strings to vibrate. Finger-picking often produces a softer tone than using a plectrum. A player can also "slap" and "tap" his fingers on the fingerboard of the guitar to produce notes, rather than plucking them.
An electric guitarist can play different notes and chords by playing the non-picking hand down on one or more of the instruments frets located on the fingerboard. By pushing down the string, the player shortens the length of that string, which causes it to raise in pitch when it is plucked or picked. A guitarist can fret up to six notes at a time, one for each string. When one note is fretted it is called a "single-line" and when more than one note is fretted it is called a "chord."
An electric guitar has between one and three pick-ups installed in the body of the instrument directly below the strings. The pick-up takes the vibration of each string and send it through the electronics of a guitar to an amplifier. Pick-ups allow an electric guitar player to adjust the tone and volume level of the instrument, as well as add effects, such as delay or distortion.