The applications lens is the first lens after the Dash home in the lens bar. The applications lens gives you access to your applications or applications available for install.
You can use Super+A to open the Dash directly at the applications lens.
Right click on a search result to open a preview. The preview shows a short description of the application, a screenshot, its Ubuntu Software rating, and what version is available.
For installed applications, you can see when the application was installed and either launch the application or uninstall it. Certain essential applications cannot be uninstalled from the preview.
For applications that haven't been installed, you can install them right from the preview.
Click Filter results if you'd like to only see results for a certain type of application. You can also click Sources ▸ Local Applications to only view installed applications or Sources ▸ Software Center to only show applications available for install.