I know faucet is used extensively in the US, I believe tap is used more in the UK and countries influenced by the UK. Faucet works for me! In the US, you will occasionally hear tap for faucet but normally tap is only used when talking about beer. I.e., what beer do you have on tap? (as opposed to bottled or canned). And when talking about the valve that lets the beer escape from the keg, you would call it a tap. I hope this helps.

I may be wrong but I don't believe there is a difference in meaning. 'Tap' is what we say in British English, 'faucet' is American English. I guess the person you were speaking to was British/familiar with British English. You won't hear 'faucet' used here so perhaps the person simply wasn't familiar with it.

In America we say faucet, saying tap is a British thing. usually in the United States tap mean tap water

In America we also say tap water to mean water from the faucet. Faucet water would sound odd. I've never heard anyone say that.

Americans plumbers use the word tap in certain instances, too.