what do you call the application that helps you to manage your website banner space?

is there a tool that helps you to manage your website banner space?

for example, client X, wants banner A for 25% of the time in a day.
Client Z wants banner A for 10% of the time in a day....

i am sure that such a tool exists. I am not finding much luck when I search in google and youtube.

interesting, i am doing manually those changes but by days, having an option of hours could be interesting, following

Ad Rotation?

You can use an ad inserter plugin on WordPress, if that's what you mean.