Zotero is made up of three components:
Once Zotero is installed look out for the Zotero icon on the top right side of your browser. The icon changes according to the type of source (reference) you are dealing with (e.g. article, book, website etc.)
A (free) Zotero.org account allows 300MB of cloud storage. This 'cloud' account operates as an online copy of the main Zotero 'standalone' account you downloaded to your device. You will be prompted to purchase a storage upgrade if you exceed 300MB of cloud storage. Read more here.
Follow the steps below to open a cloud version of your account on Zotero.org.
Step 1: Go to Zotero.org and log in/register (new account) to activate cloud storage
Step 2: This takes you to the user registration page. Complete the form and click 'Register'.
Step 3: You receive a confirmation email once your account is set up.
Step 4: Click on the confirmation link in the email.