Update aws-cloud-practitioner.md (#282)

Author: ValGrace

certificates/aws-cloud-practitioner.md

@@ -24,6 +24,11 @@ SAAS
   * IAAS
   * PAAS
   * SAAS</summary><br><b>
+ - IAAS - Infrastructure As A Service is a cloud computing service where a cloud provider rents out IT infrastructure such as compute, networking resources and strorage over the internet.<br>
+ 
+ - PAAS - Platform As A Service is a cloud hosting platform with an on-demand access to ready-to-use set of deployment, application management and DevOps tools.<br>
+ 
+ - SAAS - Software As A Service is a software distribution model in which services are hosted by a cloud service provider.
 </b></details>
 
 <details>