$q,$ is a category of cloud hosting where vendors provide hosted computers with an operating system, runtime environment, and middleware, like a Web server or a DBMS$.$

$$ PaaS $($Platform as a Service$)$

TaaS $($Technology as a Service$)$

SaaS $($Software as a Service$)$

CaaS $($Computing as a Service$)$

laaS $($Infrastructure as a Service$)$