What Is an SSL Certificate? SSL, TLS and HTTPS Explained
An SSL certificate is a digital certificate that helps a browser authenticate a website’s server and establish an encrypted HTTPS connection. It links a domain name to a public key, helping protect information exchanged between visitors and the website.
Although “SSL certificate” remains the familiar product name, modern HTTPS connections use Transport Layer Security, or TLS, the successor to SSL.
For a website owner, the practical goal is straightforward: visitors should be able to browse, sign in and submit information through a correctly configured, encrypted connection. The certificate must cover the website addresses they use and remain valid.
Ready to enable HTTPS? Explore SSL certificates at NiceNIC to compare coverage options and identity validation levels.
What Is the Difference Between SSL, TLS and HTTPS?
These terms describe related parts of website security:
- SSL stands for Secure Sockets Layer, the older protocol whose name is still widely used when discussing certificates.
- TLS is the modern protocol that secures the connection.
- HTTPS is HTTP carried over a TLS connection.
You do not normally buy separate "SSL" and "TLS" certificates for the same website. An SSL certificate product is used with the TLS configuration supported by your hosting platform or server. Mozilla's TLS documentation explains how these components work together.
How Does an SSL Certificate Work?
When a visitor opens an HTTPS website, the browser and server establish a secure connection through a process called a TLS handshake.
In a typical certificate-based connection:
- The server presents its certificate.
- The browser checks that the certificate is acceptable, including whether it covers the requested hostname, is within its validity period and chains to a trusted authority.
- The server proves possession of the corresponding private key, and both sides establish shared encryption keys.
- The browser and server use those keys to protect the data they exchange.
The certificate supports authentication; TLS provides encryption and detects tampering with data in transit. These are core properties described in the TLS 1.3 specification.
What Does SSL Protect?
A correctly configured HTTPS connection helps protect information while it travels between a visitor’s browser and your website. This includes login details, contact forms and other information submitted through that connection.
Its protection has a specific scope. HTTPS does not fix vulnerable website software, secure a compromised administrator account or automatically encrypt information stored in your database.
It also does not certify that every claim, product or business on a website is trustworthy. Chromium's explanation of browser security indicators explicitly distinguishes connection security from website trustworthiness.
For customers, reliable HTTPS removes an avoidable obstacle to using your website. Clear business information, useful content and a dependable purchase experience still matter.
Which SSL Certificate Does Your Website Need?
Choose a certificate by answering two separate questions: which addresses must it cover, and what identity checks do you require?
Choose the Website Addresses to Cover
Single Domain SSL suits one website. Check whether the selected product includes both example.com and www.example.com; do not assume every product includes both.
Wildcard SSL covers matching subdomains at one level. For example, *.example.com can cover shop.example.com and portal.example.com, but not account.shop.example.com. The base domain, example.com, must also be included separately in the certificate if you need it covered.
Multi-Domain SSL covers several specified names within one certificate, subject to the product’s limits.
Write down the exact addresses your visitors use before ordering. This is more useful than simply counting how many websites you operate.
Choose the Validation Level
Domain Validation, or DV, confirms control of the domain.
Organization Validation, or OV, adds checks on the organization behind the certificate.
Extended Validation, or EV, involves more extensive verification of the organization and the applicant’s authority.
These categories describe validation depth. Buying OV or EV does not, by itself, make the connection's encryption stronger than DV. DigiCert's validation overview explains the identity checks involved.
For a standard website that needs HTTPS, DV is often a suitable starting point. Consider OV or EV when verified organization identity is part of your business requirements.
Use the NiceNIC SSL Finder to compare these choices against your website setup.
How Do You Get an SSL Certificate Working?
Purchasing a certificate is one stage of enabling HTTPS. Validation, installation and testing must also be completed.
1. Check Your Hosting Platform
Ask whether your hosting provider already supplies and manages a certificate. If you intend to purchase one separately, confirm that your platform supports installing it.
Some managed website platforms handle certificates themselves. Checking first helps you avoid buying a product you cannot deploy.
2. Confirm Coverage and Prepare the Request
List the required domain names and subdomains. Follow your hosting platform’s instructions for generating a Certificate Signing Request, or CSR, where required.
Keep the private key secure. The CSR contains the public key and request information; it is not a reason to send your private key to a certificate seller.
3. Complete the Required Validation
Follow the certificate authority’s current instructions to demonstrate domain control. OV and EV also require organization checks.
If validation uses a DNS record, add it at the provider hosting your domain’s authoritative DNS. That may be different from your domain registrar.
4. Install the Issued Certificate
Install the certificate and any required intermediate certificates on the service handling your website’s HTTPS connections.
For websites using a CDN or reverse proxy, check how the connection from that service to your origin server is protected as well.
5. Test the Website
Check every hostname the certificate should cover. Test important pages, forms and login flows, then configure HTTP requests to redirect to HTTPS.
Review scripts, images and other resources for HTTP links that could cause mixed content problems.
6. Assign Responsibility for Replacement
Decide who will request, validate, install and test replacement certificates before expiration. If your platform supports automation, confirm that the entire process works.
Certificate issuance and installation are distinct tasks, as described in DigiCert's certificate setup explanation.
How Long Is an SSL Certificate Valid?
A certificate’s technical validity period can be shorter than the subscription you purchase.
Under the CA/Browser Forum's adopted schedule, publicly trusted TLS server certificates issued from March 15, 2026 through March 14, 2027 must not exceed 200 days of validity. Providers may issue certificates for shorter periods. The schedule is documented in Section 6.3.2 of the adopted requirements.
An annual subscription therefore does not mean that one certificate can remain installed for an entire year without replacement.
NiceNIC’s SSL page lists free reissues. Before ordering, check the selected plan’s terms and establish who will install each replacement. Reissuing a certificate and deploying it to your website are separate actions.
Common SSL Certificate Questions
Do I Need SSL If My Website Does Not Accept Payments?
Yes, HTTPS is appropriate for informational websites, portfolios and blogs as well as online stores. Visitors still benefit from a protected connection when reading pages or submitting a contact form.
Should I Use a Free or Paid SSL Certificate?
A free certificate from a trusted certificate authority can provide HTTPS. Check whether your hosting provider manages issuance, installation and renewal for you.
A paid product may be useful when you need a particular validation level, coverage arrangement or support service. Choose according to those requirements and the ongoing management involved.
The Let's Encrypt getting started guide explains the difference between provider-managed certificates and managing certificate software yourself.
Will an SSL Certificate Improve My Google Rankings?
HTTPS is part of delivering a secure website experience. Buying a certificate does not guarantee higher rankings, faster indexing or more sales.
Google's page experience guidance encourages website owners to assess the overall experience. Useful content, accessibility and a functioning website remain essential.
Why Does My Website Still Show a Certificate Warning?
Possible causes include an expired certificate, a hostname that is not covered, an incomplete certificate chain or an incorrect server configuration.
Record the exact browser error and the affected address before contacting your hosting provider or certificate support team. Purchasing another certificate without identifying the cause may not resolve the problem.
Choose Your SSL Certificate with NiceNIC
NiceNIC offers Single Domain, Wildcard and Multi-Domain SSL options, with validation choices suited to different website requirements. Its SSL service also lists free certificate reissues and 24/7 human support.
Start with the addresses you need to protect, then compare the current plans and validation requirements.
Compare NiceNIC SSL certificates to find a suitable option.
If you need help choosing, contact NiceNIC support with your domain names, hosting platform and whether you require organization validation.
