Sure. Your browser's localstorage could be used by any page/app that you visit. They all have to get along.

It's useful to know that, like cookies, the localStorage is divided by origin (essentially, the server that you are talking to). So you don't have to worry about other apps from other sites.

But suppose there's an online games site with many games. If the Bloons game saves your statistics under stats and the Zork app saves your statistics under stats, well, that's a disaster. But if they saved the status under bloons_stats and zork_stats, that works.

In the final project, your apps will save some data in localstorage, and I'll be grading all of your apps, which means my browser will visit all your pages, and they will all be hosted on cs.wellesley.edu. If every student save their data under app_data, that works fine for you, but not for me.

It would be better to have them under aa101_app_data and bz105_app_data, etc.

So, apps should try to get along by storing data under names that are less likely to conflict.