These devices contain four independent 2-input exclusive-OR gates. They perform the Boolean functions Y = A B or Y = A\B + AB\ in positive logic.
A common application is as a true/complement element. If one of the inputs is low, the other input is reproduced in true form at the output. If one of the inputs is high, the signal on the other input is reproduced inverted at the output.
The SN54ALS86 and SN54AS86A are characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ALS86 and SN74AS86A are characterized for operation from 0°C to 70°C.