Explanation:

Software-as-a-Service (SaaS) is a software licensing model. It allows access to software on a subscription basis using external servers. As its important feature, SaaS allows each user to access programs via the Internet. Thus, SaaS allows data to be accessed from any device (computer or mobile phones) with an internet connection and a web browser. The user need not install the software on his/her computer. In simple words, software-as-a-Service (SaaS)—also known as cloud based software—is now mainstream. Today’s web-based software (SaaS) is flexible enough to be modified for specific business uses but also individual users. Buyers can customize the user interface (UI) to change the look and feel of the program, as well as modify specific areas, such as data fields, to alter what data appears. Several business process features can also be turned off and on at will. Hence statements 1 and 2 are correct.

Any web-based email service is classified as SaaS, examples a web-based email service such as Outlook, Hotmail or Yahoo! Hence statement 3 is correct.