The steps needed to perform actual updates will vary depending on the type of update(s) you're trying to perform, but process for syncing updates is the same.
Click "Apply" (Bulk updates only)
Click "Sync updates"
Pro Tip: After clicking "Apply" you'll notice a green dot next to the section where you just performed updates. This indicates that the updates have been saved in Vela, at which point you can perform additional updates within as many sections as you like. Yet, just remember to click "Sync Updates" once all your work is done.