AP & GL tables

Importance tables i AP & GL

any body explain AP tables & GL tables?

Ap_batches_all,ap_invoice_all,ap_invoice_line_all,ap_invoice_distribution_all,ap_invoice_payment_all,ap_check_all,ap_check_farmate all,ap hold codes, ap bank ,ap bank bramches,ap bank account uses all,

GL Tables are

GL_JE_HEADERS
GL_JE_LINES
GL_INTERFACE
GL_Sets_Of_books
GL_code_combinations

Thanks
Chowdary