Help:Introduction to editing with VisualEditor/4
Opening the editor
How to activate editing mode
The tools at your disposal
Links and Wikilinks
Connect pages up to each other
Creating new articles
Building a page from scratch
Review of what you've learned
Once you're happy with your changes, it's time to publish them (the same as saving). When you publish your edits, they immediately change the Wikipedia page you were editing (to cancel your edits, just close your browser window).
When you're done editing, click the blue Publish changes button in the toolbar. This will open a dialog box where you should summarise your edits. This summary helps other editors understand what you've changed.
If you just made uncontroversial spelling or formatting changes, marking your editing as minor can be helpful to other editors (this option isn't available unless you're logged in). Also, if you want to be notified of further changes to the page, you can add it to your Watchlist (again, only available to those who are logged in).
The Review your changes button shows you the Wiki markup source code for the changes you've made, if you want to check. The Resume editing button returns you to the page you were editing, where you can make more changes (you can publish all of your edits later).