is a method for delivering software applications over the Internet, on demand and typically on a subscription basis. With this method, cloud providers host and manage the software application and underlying infrastructure, and handle any maintenance, like software upgrades and security patching. $q,$

Platform as a service $($PaaS$)$

Infrastructure$-$as$-$a$-$service $($laaS$)$

Software as a service $($SaaS$)$