Oracle provides two versions of SQLPlus: a command line version (sqlplus.exe) and a windows version (sqlplusw.exe). The windows version is rather primitive (ever used Windows 3.1?), but it moved many commands/options to the menus. So it may still be easier to get started with it then the command line version. However, you may be better off with the command line version after you get somewhat familiar with SQLPlus.

In SQL*Plus you can enter:

1. SQL*Plus commands. For a list of commands enter help index at the SQL prompt
   
2. SQL commands - SQL statements sent to the database. These statements are terminated by semicolon unless you change it
   
3. PL/SQL blocks - Blocks of PL/SQL code.
   

When you enter a SQL command or PL/SQL block (not SQL*Plus commands), it is saved in the SQL Buffer. The command or block remains in the buffer until replaced by the next SQL command or PL/SQL block. You can view the buffer contents with the LIST command.

You can execute the command or block in the SQL buffer using the /(slash) command (enter / on a line by itself).