Difference Between Ordinary Guitar Player and Bass Guitar Player

The "mindset" of a real bass player is completely different than that of a guitar player. Whereas, the guitar player is focused on rhythmical patterns based on melodies, as well as solos - the bass player (in a band situation) is responsible, along with the drummer, for carrying the "bottom end" of the music. This is a huge difference.
. The bass player often plays single notes, usually based on the root note of the chord being played by the guitar or keyboard. Conversely, the guitarist will often be playing or strumming multi note chords.
. Musically speaking, bass lines serve as the foundation of the song. The bass player works in close conjunction with the drummer to lay a solid foundation, and bass lines often follow the "kick" drum to solidify that foundation.
Simply put, the guitar could be considered the "icing on the cake" - while the bass might be considered "the cake".
. Bass guitar requires a different course of study in terms of music theory and notation.
. The equipment that the bassist uses is different than that of a guitarist. Bass guitars generally have less strings (4 or 5 in most cases), and the strings are a much heavier gauge than a standard guitar. This is what produces the low pitch bass sound.
Because of the low frequencies that a bass produces, a bass guitar should be played through a bass amplifier that is designed to handle the load. These amps typically are of a higher wattage than most guitar amps, and have speakers designed to handle bass frequencies.