Platform

A platform is at its core, a suite of technologies and tools provided to developers to deploy their applications on, without them needing to manage all of the extra bits around their software, like infrastructure, networking etc.

You can think of a platform sort of like Amazon for sellers. Sellers put their products on the Amazon website, without thinking about all of the extra bits like drop-shipping, warehousing, deliveries, payments etc. All of the extra bits are taken care of by Amazon. All a seller needs to think about is the product they want to sell.

That's what a platform does for developers. A platform provides software developers a place to put their code and run it, without thinking about all the underlying bits like networking, servers, monitoring, and so forth.

For example, if you have a website, and you want the world to see it, you can use Cloud Hosting to publish your website and point a domain name at it. You don't need to worry about networking, server updates, server security etc. You can simply upload your website code to the Cloud Hosting service, and they take care of the rest. They are providing the Platform for you to run your code on.