Purpose of report

Hi All,

i am trying to find out the purpose of following reports :

1) G/L Account List (S_ALR_87012328)

2) GL Account - Opening balance

3) G/L Account Balances (New) (Trx: S_PL0_86000030) GL Account - Balance

4) Financial Statement (Trx: S_ALR_87012284)

5) Document Journal (Trx: S_ALR_87012287)

6) G/L Account Statements (Trx: S_ALR_87012332)

Thanks,

Regards,

Li Quan