1)step one INSTALLATION
Once it's installed , you will get the "module install successfully" message.
2)Step two, Activation
Now , after installation ,you need to enable that module to use.
For that go to Extensions->Module Manager
Find the module and click on the "RED" color icon next to it under the "enabled" column. click on it to make it color to change to "Green" indicating "the module is enabled".
How to install the plugin
follow the same step , but after installation, go to Extensions->plugins manager and enable your plugin.
How to install component
follow the same step.
but after installation, you don't need to go anywhere unless and untill stated in the component file.
After installation , you can find the component visible in the components menu