Final answer:
The character, word, or symbol you can enter to narrow a search is called a keyword.
Step-by-step explanation:
The character, word, or symbol that you can enter to narrow a search is called a keyword. When you enter a keyword in a search engine or a database, it helps to retrieve specific information that matches your search criteria.
For example, if you are searching for information about cats, you can enter the keyword 'cats' to get results that are specifically related to cats.
Keywords are also commonly used in programming languages to define variables or functions, helping to narrow down the scope of the code.