How To Play Bass Guitar

The bass guitar has differing roles in different types of music.
The switch from upright bass to bass guitar moved bassists more into the foreground in a band setting. The smaller size of the electric bass allows rapid, complex lines to be played more easily, enabling some musicians to develop a solo role. The switch to the bass guitar allowed bassists much more freedom of movement on stage. The bass guitar is smaller, and is held up with a strap, which allows the bassist to move about on the stage while playing, and get closer to other musicians or the audience
The bass guitar player carries the beat in a band. If the drummer has a heart attack the bass guitar player is left with the job of making the room feel the beat.
The standard tuning for a guitar is E-A-D-G-B-E
A bass guitar is tuned exactly the same except that the two thinnest strings - the B and E strings are missing from four-string bass guitars, and the whole thing is one octave lower than regular guitar tuning. Also with a bass guitar you have the option of  slapping or plucking the bass guitar strings instead of using a plectrum.
A uniform sound can be given to your bass playing by using all down strokes with the plectrum instead of up and down strokes.
Since the 1980's slapping the bass strings with the thumb has become a very popular style of bass guitar playing.
If you haven't learnt to play guitar before, and you have choice between learning on a fretless or a fretted bass guitar, take the fretted one, it's easier to start with although the fretless bass gives you more opportunity for artistic expression.