There are so many potential workflows, analysis settings, and datasets within the broad field of GIS that no out-of-the-box software could contain the tools for every scenario. Fortunately, QGIS has been developed with a plugin architecture. Plugins are add-ons to QGIS that provide additional functionality. Some are written by the core QGIS development team, and others are written by QGIS users.
You can explore the QGIS plugin ecosystem by navigating to Plugins | Manage and Install Plugins. This opens the Plugins Manager window (shown in the following screenshot), which will allow you to browse all plugins, those that are installed, those that are not installed, plugins that are newly available, and adjust the plugin manager settings. If there...