Can I create my own SSL certificate?
Technically, anyone can create their own SSL certificate by generating a public-private key pairing and including all the information mentioned above. Such certificates are called self-signed certificates because the digital signature used, instead of being from a CA, would be the website's own private key.
Is self-signed certificate free?
Self-signed certificates are fast, free, and easy to issue. Self-signed certificates are appropriate for development/testing environments and internal network websites.