As a technical product manager, I'm often tasked with explaining what my team is making as well as how we're making it. After doing it for over 10 years, here's pretty much everything you'll ever need to explain your project.
The framework I use to complete this question is often used in brand-building. It's often known as a mission statement. Yes, products can have mission statements too and here's the basic framework:
Who are you? What do you do? For whom? Through what? Supported by?
What is the name of your product/service or experience?
This one is pretty simple, all you really need to do is give it the name.
What does it do?
This is where you explain what it does.
This is where you do your best to explain your market, marketshare or the people who want to consume your product. In my world, I often just refer to my cheatsheet below (see Appendix).
When it comes to digital products, this is pretty easy to explain. It's often either a website, a mobile app, a tablet app, a car app, a TV app, an API or a "new product category".
If you're a technical leader, this is a good time to list the major features required to build the app and what each feature is about. This might also be a good place to explain how we design the feature.
Another thing I tend to do is list out the various technologies and 3rd party vendors needed to complete the app. For example, will your app be built using Parse, Firebase, Mashape or something from Programmable Web?
This is where you articulate how your product will sustain itself? What's the business model or the revenue engine you think will pair nicely with the product? For example, will it be through advertising, one-time purchases, subscriptions, percentage fees, lead generation, in-app purchases, brand sponsorships, sales?
The left-hand side refers to an industry and the right-hand side describes the type of customer:
Music => Listeners, Announcers, DJ's, Musicians, Producers, Songwrites, Publishers