On the upper left-hand side of the page, you will notice a few tiles under the cloud icon. These tiles take you to App Launcher, where you can access various apps in your Salesforce instance:
Apps are a collection of tabs that can be customized. Changing the apps will change the tabs you see in your navigation. Some good examples of things you will see when you click on this tile are the Sales and Marketing apps. The Sales app has things such as Leads, Contacts, Opportunities, and other tabs that are used for the sales process. The Marketing app has these same tabs, along with the Campaign tab, which is heavily used in marketing. ...
