An SSL certificate is a website security certificate. In order for any data submitted through a webpage to reach its destination, it has to be sent over the internet.
Without secure SSL certificates, it's possible for even an inexperienced hacker to intercept that data. One of the major problems with buying an SSL certificate cheap is that you risk getting one that isn't recognized by browsers.
If the user's browser doesn't recognize the company that issued your security certificate, SSL 128 bit encryption isn't going to matter. It might exist, but if a browser doesn't trust it, your user won't either.
This is the absolute highest level of security available to any website. Although the actual encryption doesn't really change, what is noticeable is how carefully your site is vetted and checked before these highly trusted SSL certificates can be issued.
The issuing companies won't just provide the data security your visitors demand; they'll also carefully examine the documents that back up your company's existence. The end result is that they go beyond simple data security and actually provide thorough verification. This might not seem like much, but keep in mind the mindset of a typical online customer. If they're buying online, they might have never heard of you before. They have no way to go out and validate your company themselves. If you have an extended validation cert, SSL 3.0, they know that the checking and validation has already been done.
That's why these are the best SSL certificates for companies that need to go the extra mile with consumer trust - there is actually a clickable banner that will display full information about what was checked to visitors. This is an incredible confidence booster for customers who aren't certain about a site, and it can easily drive people to feel comfortable purchasing. Of course, all of this validation does require legwork on the part of the company issuing the certificate, making these the most expensive kind of digital certificates.
This is the second highest level of validation available. It provides the advantage of thorough comparison and vetting, but doesn't take quite as much time to process or dig quite as deeply into your company as extended validation. It will still provide a clickable link that gives information about your business, but it won't contain as much information as you'd get with extended validation. If you want some company-level validation for your site, this type is a good buy. Certificate prices are lower than EV.
For a long time, this was the standard baseline in digital certificates. SSL evolved originally to protect data, and that's why you'd purchase; SSL certificate design gradually grew to include validation of the business as well as security for the data. Today, even domain validation includes some evaluation. Digital SSL certificate providers will check that you have the right to secure the domain in question, hence the name domain validation.
Because this kind of validation takes the least work, domain validation are the cheapest SSL certificates you'll find. But remember before you buy: digital certificate validation is important to customers as well as their actual data protection. You aren't spending as much for domain validation and it will provide you with the same level of protection you get when you buy SSL certificates, but you're missing out on an added level of visitor confidence.
Unlike the types of validation above, wildcard SSL doesn't have a single level of user trust attached to it. Domain, organizational, and extended validation all have wildcard options available. The difference here is that a single wildcard SSL certificate purchase can cover multiple subdomains. Usually, you need to buy SSL certificate coverage for all subdomains individually. Considering the low cost of SSL certificates, if you have just one subdomain, that might not be too much of a hassle. But if you've got multiple subdomains, or plan to add more in the future, you're going to want to cover all of them with one SSL certificate. Buy a wildcard, and you're set.
These SSL client certificates cover an unlimited number of subdomains, and may even cover multiple sites on the same server. With this kind of certificate, you buy SSL once and you won't need to worry about further coverage. Although it isn't hard to get SSL certificate coverage individually, buying wildcard simplifies the process. It's usually less expensive and it's exactly the same kind of coverage you'd get from buying SSL certificate protection individually