There are different types of SSL`s. Choose between the Standard SSL (protect a domain but not the subdomains) and Wildcard SSL (protect a domain and all its subdomains).
DOMAIN VALIDATED CERTIFICATES
They are typically used for one-time validation. DV SSL`s are a good choice for simple websites like blogs, personal sites or simple presentation sites and under no circumstance, they are not meant to be used for complex websites such as eCommerce.
ORGANIZATION VALIDATED CERTIFICATES
If you are conducting any small to medium online business, OV SSL`s will be a much better fit. It will assure your customers that the certificate is from your business and the domain name is your property. Customers data such as username and password will be transferred fully encrypted.
EXTENDED VALIDATION CERTIFICATES
When you are holding big data, including personal information of your clients such as addresses or credit card details you should rely on the level of trust that only an EV SSL Certificate can provide. By using this certificate, address bar in the browser will become green, and makes it clearer to users which sites have the highest level of security and vetting.