What purpose we are using Appium Doctor Button in Appium?

In Appium why we are using Appium Doctor Button in Appium. Is there any particular purpose is there and what is the importance of Doctor Button for Appium

It verifies that all of the dependencies are set up correctly.

Thanks Christopher_Graham Giving Valuable Answer for my Question .
I understand your given Answer but not completely if u do not mind give me some example Christopher_Graham.

Hi ,
Could you share the all capabilities you used.

Still I am getting the same error.

Thanks,
Ashish Bajpai

Appium doctor verifies that all dependencies required for starting the Appium server are there or not.
In simple words it checks whether the node.js, JAVA, Android SDK are installed on the system( more specifically the environment variable of these are setup)

https://saucelabs.com/resources/appium-bootcamp/ch_1_3_appium_doctor600x477.png

If all green you have setup the Appium properly.

For the above stat of Appium Doctor you are good to go with iOS testing but you have to fix the error before you can proceed with android.

Thanks pr4bh4sh for giving Answer to my Question