A query string is the the value that appears after a ? in a URL. A query string can have multiple sets of keys and values separated by an & . A key appears before an = sign and the value appears after an equals sign.
Here is an example of query string in a URL: https://madebyspeak.com?color=red&size=medium.
The query string is:
There are 2 sets of keys and values the query string: