ELI5: Explain Like I'm 5

Card file

A card file is a kind of filing system like a file cabinet. It is made up of a box that has slots called drawers. Each drawer has thin cards that are like little pieces of paper. You can write information on a card and then slide the card into the drawer. That way, you can organize the cards by topic. For example, you could have one drawer for people's names, other drawers for their addresses, and other drawers for their phone numbers. That way, you can store all the information about a person in one place. You can quickly look up someone's information in the card file by taking out the drawer with their name and then looking for the card about them.