The Content Selector consists of all the tools in the sidebar that are available while you edit your page. It allows you to:

Content Selector.png

To add an internal link to other content within Canvas, highlight the text you want to turn into a link or simply put your cursor where you want the link to appear. Next, select the Links tab on the Content Selector on the right-hand side of your screen. This will list all of the content you have in your course. Click on the item you want to link to and the highlighted text will become a link to that item.
To add a file to your page, put your cursor where you want the file to appear. Next, select the Files tab in the Content Selector. If your file has already been uploaded to Canvas, select it from the file manager. If not, upload the file using the "Upload a new file" feature.
To add an image to your page, put your text cursor where you want the image to appear. Next, select the image tab in the Content Selector. If your image has already been uploaded to Canvas, select it from the file manager. If not, upload the image using the "Upload a new image" feature. Once the image has been inserted on the page it can be moved, centered, or adjusted inside the RCE.

To explore more detailed information about each of these subjects click on each of the links below.