How https works?

There are many possible ways when you are accessing any https hosted resource :

1.  When you request from browser for any https websites  site like 'https://google.com', the process will be as follows:

 

public key :  The key which used to encrypt the data.

private key : Every public has corresponding private key which used to decrypt the data encrypted by corresponding public key.

CA (certificate authority) : CA are who signed the certificate,  they sign the certificate using their        public key. Browsers generally comes standard CA certificates like Google CA certificates.

2. There is a case when you are developing your own web app and you want to host on https web server.

In this scenario we need to have self signed certificate because in this case google or other CA will not go to sign your certificate.

And when any application try to communicate with your application they need to have your certificate inside their trust store.