What certificate to choose?
The three types of SSL come in two sorts: single domain or wildcard. A single domain SSL certificate will protect a single domain (like www.domain.com and domain.com). Want to protect unlimited subdomains (like webmail.domain.com etc)? In that case you need a wildcard certificate.
Domain Validation (DV) is perfect when you need a certificate quickly. Organisation Validation (OV) is for company information and offers more trust than domain validation. Extended validation (EV) show the green bar and indicates that you have an authenticated business. It is the best protection against phishing or other malicious activity and it provides the highest degree of security and trust.