The IC HT12E can be used only with its pair HT12D. These two ICs together form an Encoder and Decoder pair. They are 12-bit Encoders/Decoders, meaning they can transmit 12-bit a data among them. But your encoder IC should not communicate with someone else decoder IC, so an Encoder and Decoder IC pair will share a common Address which is an 8-bit data. So out of the 12-bits 8-bits will be used to set address and the remaining 4-bit will be used to transmit data.
With 4-bit data we can create 16 types (2^4 =16) of combinations. These IC’s are commonly used with RF pairs or IR pairs. So if you are working on a project which has to transmit a 4-bit data from one end to other either by wire or wireless then this IC pair will be best suited for you.
Used to convert Parallel 4-bit data to series data
Highly useful in wireless communication projects involving RF or IR
Remote controlled systems like garage doors, Car alarm system, Car door controls etc.
Can be used in Home automation for short range remote switching
Safety systems like Burglar alarm system, Smoke or Fire alarm system etc..