With the Helix application structure of sitecore projects there are a lot of web projects. If you follow the Habitat tooling there is a set of convenient gulp tasks for publishing changes like the "do it all"
gulp default task. In most cases publishing the web project you made your changes in is enough. In most cases this is a feature or foundation project. You can do this by right-clicking on the web project, select Publish..., and press the Publish button in the resulting screen. A faster way is to enable the Views > Toolbars > Web One Click Publish option so you get a button on your toolbar for fast publication.