This food example provides a simple comparison between IaaS, PaaS and SaaS.
Lets start will SaaS, So you simply order food using a food delivery app. Now here you just need to specify what you want to eat and pay for it. No need to worry about how the food is prepared, which ingredients are used, what is the brand of ingredients used to prepare your food, whose going to be the delivery guy, is he driving too fast or slow…nothing to worry just open the door and accept the doorstep delivery of ordered food and pay for it.
Now PaaS, Here you don’t order food as we did in SaaS instead we come out of our house and directly go to the restaurant where we want to eat. In restaurant PLATFORM(chairs, tables, dishes, spoon) is provided. We simply utilize those provided platform. But here we don’t have any say in what brand of ingredients are to used or how food is to be prepared its all in the hands of chef.
Finally comes IaaS, Here we directly go inside the kitchen of restaurant and we just give a look to the chef that says “Get Aside I will prepare my own food”. Now here we get the highest degree of freedom as compared to SaaS and PaaS. We can choose what brand of ingredients to be used, which vegetables/oil/ is to be used, the way food is to be prepared is all in your control.