Wordpress plugin setting data

I want to know that where the plugins settings data saved in server? Means, when we change any plugin settings (e.g. For simple captcha, it is settings as-> use number, user alpha, captcha color etc), then in which file or database , these settings are saved.

All settings of the Plugin will be saved in the db.

Your Plugin can choose which table they wanted to store the setting into. Check the source code of your Plugin.

• If your Plugins uses get_options(), then it will stored in the wp_options table
• If your Plugins uses get_post_meta(), then it will be stored in the wp_postmeta table
• If your Plugins uses get_comment_meta(), then it will be stored in the wp_commentmeta table

Your Plugin might also have created its own table to store the settings.