It is very important to read these. Global items are a major feature of the website. They keep the layout of the site uniformed to all the pages.
How to edit and what to avoid with a global item.
Note: Global items within the page builder are easily identified by their green color. If you are editing a module, row or section that is green, or if the current modal settings window that you have open is green, then you know that you are currently editing a global item. It’s important to know when a global item is being edited, because any change you make will be mirrored across every page that item has been placed on.
Edit those that have red icon on the left side.
Edit fields that have a green icon on the left side.
In this case you can edit the Title (red), and you can’t edit the Content (green).