MC14071 IC consists of 4 independent 2-input OR gates. OR gates are used to perform logical addition operations. These are useful in building logic level circuits like Encoder, Decoders, multiplexers, etc.
CD4011 is a member of the CD40xx CMOS IC series. The CD4011 IC contains four independent NAND gates. The devices perform the Boolean function Y = A × B or Y = A + B in positive logic. This IC is used in AV Receivers, Portable Audio Docks, and Blu-Ray Players.
The CD74HCT20M is a high speed CMOS Logic dual 4-input NAND Gate. The logic gates utilize silicon gate CMOS technology to achieve operating speeds similar to LSTTL gates with the low power consumption of standard CMOS integrated circuits.