When you install a plugin within WordPress, the plugin must be activated, or switched on before it can be used. This simple one-click process can be done within the WordPress Dashboard.
Make sure that you see all the plugins; if not, click the All link under the Plugins page title.
The Activate link appears beneath the name of your plugin, as shown in Figure 2-12.
The Plugins page appears with a message confirming that the plugin was activated, as shown in Figure 2-13.
To deactivate a plugin, follow the same steps, but instead of clicking the Activate link, click the Deactivate link, as shown in Figure 2-14.
The process of activating and deactivating plugins is very simple and easy to do within the WordPress Dashboard. Remember to watch for error messages and follow the plugin developer's support instructions when you need help.