different between stereo and sound equipment
i would like to know which is the different between these two words that is to say what word is more used
That is a very good question! They are not the same, but they are related.
Stereo means the left and right channel are different. A LONG time ago, sound from phonographs or the radio was monaural, meaning there was only one speaker or if there were multiple speakers, the sound that came out of them was all the same.
Then came stereo with left and right channels. And now we have "surround sound" with 5.1 Dolby (2 front, 2 rear, 1 center + 1 sub-woofer).
"Stereo" came to mean the record player/radio/tape player/speakers. "Turn on the stereo, I feel like dancing!" "That car has a great stereo system."
Sound equipment is used more to talk about individual units, components, or objects related to sound. For example, the microphone, amplifier, speakers, reel to reel recorder, equalizer... these are all sound equipment. You use the words "sound equipment" when you talk about a concert, or a lecture, or a church.
Personally I would refer to car or home audio as "a stereo" if it was purchased as a set, and "sound equipment" if the person bought the individual components to make a complete system. This is just my sense of the words, though, and certainly it is not part of the definition.