What an SSL certificate is
An SSL certificate is a file that proves a domain is genuine and lets the browser open an encrypted connection to the server over HTTPS. Without one, everything travels in plain text: passwords, form contents and card numbers can be read by anyone controlling a segment of the network in between — from the owner of a public Wi-Fi hotspot to an internet provider.
The term SSL is long obsolete: that protocol has been retired and all modern encryption runs on TLS. The old name stuck in everyday use, so certificates are still called SSL even though technically they are TLS certificates.
Types of certificate
Certificates differ not in the strength of the encryption — that is identical everywhere — but in how thoroughly the owner is verified and how many domains are covered.
DV (Domain Validation) — only control over the domain is checked. Issued automatically within minutes and suitable for most sites: blogs, company pages, online shops.
OV (Organization Validation) — the legal entity is verified as well. Company details end up inside the certificate, which matters to banks, public bodies and services handling sensitive data.
EV (Extended Validation) — extended verification of the organisation against documents. These used to produce a green bar with the company name, but browsers dropped that in 2019: Chrome, Firefox and Safari now display every valid certificate the same way.
Wildcard — covers the domain and all its first-level subdomains at once, convenient when a project consists of many services. Multi-domain (SAN) — one certificate for several different domains.
Why you need one
Beyond protecting traffic, HTTPS is now simply a precondition for a site to work properly.
Browsers mark pages without a certificate as “Not secure” and attach an explicit warning to password and card fields. To a visitor that reads as a reason to close the tab.
Search engines treat HTTPS as a ranking factor and, all else being equal, prefer the secure version of a site.
A number of modern technologies are unavailable without HTTPS at all: HTTP/2 and HTTP/3, Service Workers, geolocation, camera and microphone access, push notifications. Payment systems and APIs often refuse to work with insecure addresses.
How to obtain and install one
The steps are the same for any certificate. First a private key and a signing request (CSR) are generated on the server. The certificate authority then verifies control of the domain — usually through a file on the site or a DNS record. Once verified, the certificate is issued and, together with its trust chain, written into the web server configuration. What remains is to enable the redirect from HTTP to HTTPS and check that every resource on the page loads over the secure protocol.
The free option is Let's Encrypt: certificates are issued automatically for 90 days and renew themselves. This is exactly what control panels such as ISPmanager, cPanel, aaPanel and Plesk use — there it takes a single button. For a DV certificate, a paid one adds nothing to the level of protection.
Paid certificates make sense when you need organisation validation, a warranty from the authority or support from its technical team.
Certificates on our servers
Dedicated and virtual servers come with full root access, so you are free to install any certificate — a free one from Let's Encrypt or one bought from any certificate authority. The platform imposes no restrictions: not on the choice of authority, not on the number of domains, not on the validation type.
Configuring the web server and issuing certificates is up to the server owner. With a control panel installed, the whole process comes down to a few clicks in its interface.