Switching between two appliances on a single power socket

Something like this perhaps? Your question is somewhat ambiguous but this sort of independently controlled power strip appears to meet the requirement:

The answer depends upon power demands of the "appliances". If they have high power needs like a clothes dryer, water heater, electric range, air conditioner, etc. that would be a different approach than simpler 120v appliances. You'll need to source a switch with the correct rating. Also, heavy duty appliances would need to have similar power requirements. I assume you want to do this because you have very limited electrical supply? Off grid solar? or in your country, very limited power?

Here is a starting point. You'll want to consider local code compliance where you are as well.