For example when you have multiple lines of very similar code, and you change each instance simultaneously
Hi @brandonalexandertong, welcome to the Glitch forum!
The Glitch Editor supports multi-line editing. If you have identical code you wish to refactor you can select one instance of it and use Cmd+D (on a Mac) / Ctrl+D (on a Windows machine) to select the other copies of the same value.
Alternatively you can Cmd+Click / Ctrl+Click in multiple places to create multiple cursors and work from there.