difference between encoder and decoder?

[gursimran_2006]

what is the difference between encoder and decoder?

 

[n2casey]

Encoder encodes the file in specified format while decoder decodes it.

 

[anandk]

Encoder encodes ...while decoder decodes...

pls explain in detail what this means to him.

 

[shashank4u]

encoding ,decoding can be seen in two ways ..
#one is signal processing or in transmission:
encoder provides single channel output for multiple inputs..for distribution purposes while decoder do just opposite..

#and the other is in format change(compressing decompressing algos.)
for audio or video files..
hope this helps..