Words rhyme with each other if their endings sound the same. They do not have to be spelt the same way.

Hear rhymes with beer.

Sty rhymes with pie.

Toe rhymes with slow.

Sometimes words do not rhyme even though they are spelt in the same way.

For example, great and cheat both have the letters  'eat', but if you say them out loud you will hear that they don't rhyme.