what is the difference between commercial SSL and with manual setup with nginx . guide is here https://www.digitalocean.com/community/tutorials/how-to-create-an-ssl-certificate-on-nginx-for-ubuntu-14-04 ?
Mike
Commercial ones as you called them are TRUSTED. Therefore a browser won't be suspicious when it receives it, but when it receives the self-signed one it'll warn the user that the it has no way of trusting the site, even though the same SSL Protocols can be employed; the security isn't downgraded but can be an annoyance and could deter clients if it was a public Website. For private projects there is nothing wrong with self-signed as it is still same security. There are free ways to get Commercial SSL Certs such as StartSSL or WoSign: https://buy.wosign.com/free/
is this trusted company ? https://buy.wosign.com/free/ did you try? looking like some Chinese. I think better to buy SSL with domain and from hosting provider. thanks for help guys
Yes - their certificates are trusted.
Just in case you worry about the country of origin I'd take webdevgurus suggestions above and check out well established services like startssl.com
If by "manual" you mean self-signed then the difference is that browsers do not trust self-signed certificates because anyone can self-sign a certificate for any domain. When you buy a certificate the authority will verify that you own the domain and browsers are configured to trust these commercial authorities.