It's more than a web browser. Your Chromebook can run real apps without an internet connection.
Chromebooks have a reputation of being an online-only machine. While that was true when they first came out, things have changed. There's no doubt that having a connection to the internet is the best way to use a Chromebook — or any laptop for the most part — but Chrome OS has evolved and there are plenty of apps that let you do your thing while you're not online.
Since the introduction of what Google called "Packaged Apps" it's been fairly easy to build applications for Chrome that can be self-contained and run everything locally. Chrome has a file system, and programs can store data and retrieve it as needed. We tend to think of Chrome as a browser, but it's more. It's a full fledged application platform, and designed to let third party programs run outside of what we call the browser window. You don't have to do things the same way Microsoft or Apple does to bring "real" applications to life, and Google — as well as plenty of others — are doing just that.
If you visit the Chrome store, you'll find a nice selection of games, text editing and writing tools, entertainment features and utilities that don't need an internet connection to run. You'll even find tools web developers can use to package their own applications to work with Chrome while the user is offline. Familiar companies like Autodesk and Amazon have apps to use offline, you'll find code editors for just about any language, and you can even play Cut the Rope without a network connection. All the apps you'll find aren't great (another thing you'll find on any platform) and there are some serious holes in the selection if you need to do professional-level video, photo or audio editing. But with apps like Kindle and Evernote and Pocket available, as well as being able to play music and movies while you're not connected, you'll find plenty to do without a WiFi connection.
Google is well represented here, too. You can pin movies and TV shows through Google Play Movies and TV, use your calendar and email just like you would on any laptop offline, and you can even set up Google Drive to keep local files in sync with the same cloud you would use on any other computer — including your phone. And enabling offline mode in Google Docs allows you to use apps for word processing, spreadsheets and presentations any time you like that can easily be kept in sync online when you do have access to the internet.
Of course, every laptop is better with an internet connection. The web is the platform of the future, and we see Microsoft and Apple making their web services better every year, and making great ways we can use them from our computers. Google has a leg up here because they have been an internet-first company since the beginning. As they continue to improve Chrome — and get users familiar with the idea of Chromebooks by getting schools and businesses on board — the gap between Chromebooks and "real" laptops, whether genuine or perceived, will continue to close.