Opamps used in low voltage applications
They tend to be called rail to rail, or R2R amplifiers. They can be R2R on input only, output only, or both.

Many use CMOS internally, though bipolar designs also exist.

With low voltage gadgets, their creation has been a necessity. In the bad old days, high voltage rails were the norm (+/- 15v), and bipolar designs happily stayed a volt or three away from the rails. You can't do that with battery powered devices today.