All and every can both be used to talk about people or things in general. There is little difference of meaning. Note that these two words are used in different structures.
Every is used with singular countable nouns. To give the same meaning, all is used with plural nouns.
- All children need love.
- Every child needs love.
All can be used with determiners. Every cannot normally be used with them.
- All the lights were out.
- Every light was out. (NOT Every the light —)
- I have invited all (of) my friends.
- I have invited every friend I have. (NOT — every my friend.)
With Uncountable Nouns
We can use all with uncountable nouns. Every cannot be used with them.
- I like all music. (NOT —every music.)