There are times where you need to store those library-type scripts/styles in one place to be reused. Storing your code templates for reuse can help streamline your development processes and help keep everything managed and organised. There are two main systems that work together for templating code, and they are the Templates Manager and the Templates Panel.
Templates Manager (under Tools -> Templates)
Centralise your library/third-party codes by linking templates, which is using WordPress scripts/styles queue to avoid conflicts. It provides all the tools needed to create, edit, delete, and manage all of your code templates in one main table.
Templates Panel (under Panels -> Templates)
The Templates Panel allows you to use any of your templates that you created in the Templates Manager. You have a choice of either embedding the template directly into the coded block or linking the template to the code block. Embedding a template copies and pastes the entire template code into your code block, making it easy to see and make changes to the code. Linking a template, makes it ideal for linking multiple templates. The Templates Panel also allows you to embed or link to WordPress built-in scripts/styles (e.g. jQuery, Thickbox, etc) that are bundled with WordPress. These are often minified, so using the Beautify function will make it nice and readable.
Once you have embedded or linked templates to code blocks, you can then assign it to WordPress Pages, Posts, Custom Posts, Categories, Tags, and basically all the locations in the Assignment Panel.
External Script (under Panels -> Templates)
This handy feature can be used to automatically create templates from a third-party script. It works by downloading the third-party script (e.g. from a CDN such as jQuery), adding it as a new template to the Templates Manager, and linking it to the current code block. All of this is done automatically and seamlessly behind the scenes, and from a single click of a button. No need to worry about hot-linking to the third-party server hosting the script and worrying if it will one day be removed.