Toolbox is a side bar filled with liquid shortcuts for inserting various items into Pages, which makes for quick and efficient editing and also means you don't need to remember the specific line of code or item IDs to output data on your page.
You can insert any of the following elements from Toolbox:
Site Search Form, and Results - this allows visitors to quickly find what they're looking for
Insert Form - this allows you to add a Form that you have made in Forms
Insert Image - inserting an image from your device, in here, you can see already uploaded images to your site that you can add to this Page too quickly
WebApps - inserting WebApps that you have made, to this page
Modules - insert a Blog, Authors or FAQ
Secure Zones - insert a member's area or other Secure Zone that you have made
eCommerce - inserting a cart, checkout, and a product list
Insert Menu - insert a Menu that you have made, containing your important Pages that every visitor may want to visit (this can added into your Template in your Header so be careful of duplicate Menus)
Insert Code Snippet - such as a starter kit eCommerce sidebar
Insert Content Section - this can also be used to insert a sidebar
Insert Footer - inserting a Footer that you have made in the Site Manager
Insert Header - inserting a Header that you have made in the Site Manager
Insert Company Information - inserting information that you have put within the company information tab in CMS, this is extremely handy for an about Page.
Where can you find Toolbox?
You will see Toolbox to the right-hand side of your screen, from any of the following locations in Admin: Pages, Headers, Footers, Templates, Content Sections, Code Snippets, System Pages and System Emails.