There are many varieties of English other than British and American. All of those other varieties are intrinsically just as worthy of study and use as British and American. But these two varieties are the ones spoken by most native speakers of English and studied by most foreign learners.

American English                                                     Britsh English  

To graduate from school                                        To finish school​

A graduate course                                                  A postgraduate course  

A freshman                                                               A first-year student 

A sophomore                                                            A second-year student 

A junior                                                                       A third-year student 

A senior                                                                      A fourth-year student

A Student                                                                  A Pupil

A semester                                                                A term

Instructor                                                                  Lecturer

Review                                                                        Revise

Grades                                                                        Marks

It is necessary to highlight that British English and American English are only varieties of English, not two separate​ languages. There are several differences in grammar and pronunciation. The most noticeable difference between American and British English is vocabulary.