What is the difference between a Piano Teacher and a Concert Pianist ?

What are you asking? I'm assuming that you've noticed the big, obvious difference that the names give away.

Generally a concert pianist needs to be of an extremely high skill, while a piano teacher can get away without being so virtuosic. A concert pianist plays the piano to entertain people and show off, a piano teacher must teach their student how to play and love the piano. Being a piano teacher probably requires more patience than being a concert pianist.

Not that the two are not interchangeable. Many concert pianists have students and teach in their spare time to make a bit of extra money. And many piano teachers are fabulously virtuosic, and the little squits who mess around in their piano lessons don't have any idea how lucky they are!

In the music world, a concert pianist is a solo performer, someone who is invited to play with orchestras and in solo recitals. They're the people who make the recordings sold by major labels. They might also have some advanced students who are training to be concert pianists themselves.

A piano teacher is someone who teaches piano, usually to kids, and the technical requirements aren't nearly as high.

a concert pianist is a person who performs piano music at concerts (usually very skilled at piano) and a piano piano teacher is a person who teaches piano to students

Proper, structured piano practice helps you stride forwards. Learn here https://tr.im/PianoForAll

I say ‘proper’ because a lot of people have an idea that practice IS just playing songs over and over. Practice needs to involve unchartered territory.

The golden rule is practice what you can't play, not what you can play

No more difference than there is between a used car salesman and a race car driver.