SSL stands for Secure Socket Layer. When a customer fills out a form on your website or makes a purchase their information is sent to your website hosting to be processed, without an SSL this information could be intercepted and stolen but with an SSL certificate it gets encypted before it gets transferred and decrypted when it reaches its destination safely.
This is the most commonly asked question and the answer really depends on your budget and your needs. Generally we advise our customers to get a paid SSL, we offer them at a very low cost and it includes installation and configuration. The paid SSL also offers a higher level of security and a gaurantee from Symantec. You can read a full comparison of Free vs Paid SSL on our sister company's blog.
No, you must purchase an SSL for all of your sub domains that you require it on. E.g. mail.yourdomainname.com and www.yourdomainname.com would require two SSL certificates. If you have a lot sub domains you could mix and match between Free and Paid SSL to keep the cost down or contact us about a wildcard certificate that can cover all of your sub domains.
Google don't release information about how their ranking algorythm works so we cannot say with 100% certainty that SSL is beneficial for your ranking, however, Google recently released a statement informing people that non secured websites will be clearly marked as "insecure" from July 2018. Read the full article here. This statement is an excellent indication that the search engine giant is going to favour your SSL secured website over a non SSL one!
