Redis Command: DECR

Decrease the value stored in by One(1). If the key does not exist then this command will set the key and the value will be Zero(0), before performing the operation. And after the operation is performed, the value will be negative one(-1). If the value is not an integer, like a string that can not be covered to an integer, or a list, set, etc. then this command will return an error.

Redis Command: INCR

Increase the value stored in by One(1). Used when we want to increase some count by one. For example, we want to save- Total number of logged-in users, Number of times the user tries to log in or reset the password, Number of times the user tries to access some resource or API endpoint.

Redis Command: APPEND

Append the provided string to the existing string value of a . If the key does not exist then this command creates the key first with an empty value, then appends the provided value to that empty string. In case the does not exist then the APPEND command behaves like the SET command.