What is meant by (up to Isomorphism ) ?

Qn: Sir what is meant by (up to Isomorphism ) Ans: The phrase "up to isomorphism" means "any such things are isomorphic". For e.g count 1, 2,3,... in English, Tamil & Hindi. Counting words are different but they mean the same. This concept is Isomorphism. Two groups (rings, fields) are Isomorphic means they have same structure (they behave alike). Hope you understood. - Prof. Suresh.