class roster and class register

Hi teachers ,

On the internet  I see teachers of many schools  talk about the following words and I don't understand exactly their respective  meanings:

a/Class roster

b/Class register 

c/Teacher's  personal mark book

d/Grade book

Please help clarify their meanings.

Thank you in advance

Hi Mister Micawber ,

No, you sure did not waste your time , I do appreciate your great help greatly . I was really still confused about their meanings until your explanation this time.I did try hard to consult many dictionaries but couldn't find their meanings . Thanks to your help , now I am clear about it.

Sorry again for having troubled you on this Sunday morning , but teachers in this forum  like you , Clive, Avangi , Grammar Geek etc., are the only persons who can help me ,apart from you all here , I don't know who to ask for help about English . Deep in my heart I am always grateful to all teachers in this forum ,who have sacrificed their precious time to help students like me .

Best wishes