# EPOC OPL Guide & Reference Glossary

## Index K

Term | Topic | Meaning | See Also
key | Data File Handling | One or more columns in a database used for ordering it in an index. |
keyword | Introducing OPL | A word in a program with a special meaning to OPL. OPL keywords are usually program instructions, although other types of keywords exist. |
keyword | OPL Basics | A word with a special meaning to OPL that performs some action when used in a statement. You can’t use keywords for variable or constant names. | statement, variable, constant