Dropbox allows you to share a photo or video folder with others. You can send invitation to others to view your folder or vice versa. If someone has invited you to a shared folder, then you can join it by accepting the invitation. To learn how to accept a shared folder invitation, and how to request access to a shared folder, check out the steps below.

Here are the steps to Accept a Shared Folder Invitation:

1. Go to https://www.dropbox.com/ & sign in to your account.
2. Once you have signed in to your account, click "Sharing" located at the sidebar on the left.
3. Click "New shared folder invitation" link located at the top of the page.
4. A pop-up window opens up.
5. Click "Accept" button located next to the shared folder which you want to join.

If you click a shared folder invitation and you're directed to request access, the folder owner may not yet have given you access. You will need a verified email address to complete your request.

Here are the steps to Request access to a Shared Folder:

1. Click the invitation link that you received.
2. Click "Request access" button located on the page.
3. If you have more than one Dropbox account, you will get a message "Which Dropbox do you want to use to request access?"
4. Select which account you would like to accept the shared folder.
5. Your request will be sent to the folder owner.
6. You will get notification if the owner accepts your request.