The usual string bending for most people is either a whole tone bend (equivalent to bending to a pitch two frets up) or half tone bending (bending to a pitch one fret up).
Named as interval they are bends of a major second and a minor second respectively.
Intervals are in Practical Music Theory Module 5.1.
Or here: Intervals, scale degrees and more
Some guitarists like to play more extreme bends. Bending a note the equivalent of three frets is often called a one and a half tone bend. In interval terms it is a minor third. Even more extreme, a bed equivalent to four frets up is a major third bend, or two tones. Not for the faint hearted or someone new to bending techniques. And very rarely used.