What are plugin resources?
Your plugin may include a variety of additional resources in the "application/plugins/your_plugin/install" folder that system will automatically load into the database upon plugin installation. These resources include language items, configuration data, email templates, meta tags, etc. This saves you a lot of time since you don't have to write database queries manually to insert data into the database tables, especially when making updates for your plugin. Simply update these files and system will automatically make necessary changes in the database. All of these files are optional, meaning that your plugin will install fine without them.