The website information security encryption has been more and more people's attention to the site will be used to encrypt the SSL certificate. So we choose the ssl certificate when, how to choose?
First we have to know the type of SSL certificate, which has several, generally divided into:
1, DV SSL certificate type
that the lowest level of security certificates, for personal and small business websites website
2, OV SSL certificate type
business type certificate, the security level higher, but more cumbersome to apply, personally recommend using OV type SSl certificate, cost-effective.
3, EV SSL certificate type
highest level of security SSL certificates, can be seen as DV, OV enhanced version, the address bar green, but also show the company name
as shown: 
After determining the type of SSL certificate, and then determine do a single-domain certificates, multi-domain certificate, or pan-domain certificate. As shown below. 
Finally, determine the SSL certificate brands to choose what kind of.
SSL certificate purchase and installation can refer to: a letter SSL