This lesson covers a few components that will let you make forms more powerful. Form memory lets you save the user form input to Local Storage. Imagine you have a long form that users have to fill in and they reload the page by mistake, or you redirect them to different pages in the meantime on purpose. When user gets back to the form, all the data are automatically filled in and remembered. Form hidden field lets you send additional information with the form that is filled in by your users. Imagine, you want to get the information about the partner, that sent the user via referral. When user fills in the registration form, together with the input data you will receive the name of the partner. You accomplish that with the query string, meaning, you can dynamically pass different information to the form depending on the source or campaign. Finally, Form Prefill lets you pre-fill form data with some information. This might help the users so that they don't have to type in the information that you already know (eg. their name when you redirect from an email) or pass the information that they might not know or are hard to find (eg. partner name or invoice number).