F1 provides you with explanations for fields, menus, functions, and messages. In the F1 help, you can choose to get technical information.
F4 gives you information and possible entries. You can also use the F4 help by choosing directly to the right of a selected field.
Further help can be found in the help menu. Choose Application Help for context-sensitive help on the transaction you are currently using. Choose SAP Library to open the online SAP Library. You can also access it on the Internet at help.sap.com.