_TL, _VL, _ALL, _B, _F, _S tables in Oracle Apps

_ALL: These are Multi-org tables where we can see data for all operating units.
Ex: oe_order_headers_all, oe_order_lines_all, po_headers_all ap_supplier_sites_all

_TL:
These are translated tables which have the translated value for each installed language. These are tables corresponding to another table with the same name minus the TL. 
These tables provide multiple language support. 
For each item in the table without TL there can be many rows in the _TL table, but all with different values in the LANGUAGE column.
Ex: fnd_responsibility_tl, oe_transaction_types_tl

_F
These are date tracked tables which occur in HR and Payroll. In these tables there are two date columns EFFECTIVE_START_DATE and EFFECTIVE_END_DATE which together with the PK identifies a row uniquely. The date intervals cannot overlap.
Ex: per_all_people_f, per_all_assignments_f

_B
These are the BASE tables. 
They are very important and the data is stored in the these table with all validations.
It is supposed that these table will always contain the perfect format data.
If anything happens to the BASE table data, then it is a data corruption issue.
Ex: mtl_system_items_b

_V are views.

_VL
These are views for multi language tables which combines the row of the base table with the corresponding row of the _TL table where the LANGUAGE = USERENV('LANG'). 

_S are sequences, used for generating new values for the primary key of a table.