updating and editing/adding content

Hi everyone,

So I'm about 1/3 of my way into the course, and have a question regarding updated content. Once I post my course, and students enrol - I know I cannot delete it, but, can I update say a slide that is outdated? Also, and more so, if students are asking a lot of similar questions - can I add additional content to the course? i.e. a new video explaining something perhaps that was missed the first time around?

Thanks all