Think of a field as a single answer blank on a questionnaire. A field is any single and separate bit of information that you want to allow the computer to sort by.. That is, if you want to sort and analyze the information by state, you will need a separate blank on the questionnaire for "state". If you want to sort by cities within the state, then you would need a separate blank for "city" In the normal database (and on the normal questionnaire) you would want to put a person's first name, last name, street address, city, state, and zip code into different fields. By so doing, you could have the computer list people alphabetically by first name, last name, , street name, zip code, etc.
For more information on databases and how to use them, check your local library, or see the operating manuals for any database software program. See also, "database", "record", and "GIGO".