Shared folders are great for groups of people to collaborate on a set of files. Any changes that are made to the files are automatically synced to everyone belonging to the shared folder.
There are several different ways to create a shared folder. You can create a shared folder from the file system by right-clicking on the folder and clicking "Share this folder". In the web interface you simply select a folder and choose, "Invite to folder". Lastly, you can click on the Sharing button in the left column of the web interface. You can either create a new folder or choose an existing one.
In each case you will be asked for the email address of the collaborates that you wish to invite to the folder. You can optionally enter a personal message that will display in the invitation email.
Keep in mind that shared folders use up everyone's individual storage quota.
You can create a shareable link to any file or folder in your Dropbox account. When a user receives the link they are presented with a nice interface
Simply click "Get Link" in the context menu on the file system, browsers, or click on Link icon on mobile devices. This is a quick and easy way to share files with anyone. The great thing about this feature is that thay don't need to login to Dropbox to access the files or folders that you've shared with them.
Dropbox for Teams
If you have a groups of users that professionally collaborates on files, then Dropbox for Teams is a perfect solution. It allows groups of 5 or more to share a minimum of 1TB of storage.