What is SSL Certificate?
SSL, more commonly called TLS, is a protocol for encrypting Internet traffic and verifying server identity. Any website with an HTTPS web address uses SSL/TLS.
SSL certificates are what enable websites to move from HTTP to HTTPS, which is more secure. An SSL certificate is a data file hosted in a website's origin server. SSL certificates make SSL/TLS encryption possible, and they contain the website's public key and the website's identity, along with related information. Devices attempting to communicate with the origin server will reference this file to obtain the public key and verify the server's identity. The private key is kept secret and secure.
In addition to securing user data in transit, HTTPS makes sites more trustworthy from a user's perspective. Many users won't notice the difference between an http:// and an https:// web address, but most browsers have started tagging HTTP sites as "not secure" in more noticeable ways, attempting to provide incentive for switching to HTTPS and increasing security.
Why SSL Certification?
A website needs an SSL certificate in order to keep user data secure, verify ownership of the website, prevent attackers from creating a fake version of the site, and gain user trust.
Encryption: SSL/TLS encryption is possible because of the public-private key pairing that SSL certificates facilitate. Clients (such as web browsers) get the public key necessary to open a TLS connection from a server's SSL certificate.
Authentication: SSL certificates verify that a client is talking to the correct server that actually owns the domain. This helps prevent domain spoofing and other kinds of attacks.
HTTPS: Most crucially for businesses, an SSL certificate is necessary for an HTTPS web address. HTTPS is the secure form of HTTP, and HTTPS websites are websites that have their traffic encrypted by SSL/TLS.
How to obtain?
For an SSL certificate to be valid, domains need to obtain it from a certificate authority (CA). A CA is an outside organization, a trusted third party, that generates and gives out SSL certificates. The CA will also digitally sign the certificate with their own private key, allowing client devices to verify it. Most, but not all, CAs will charge a fee for issuing an SSL certificate.
Once the certificate is issued, it needs to be installed and activated on the website's origin server. Web hosting services can usually handle this for website operators. Once it's activated on the origin server, the website will be able to load over HTTPS and all traffic to and from the website will be encrypted and secure.
Many website hosting providers and other services will offer TLS/SSL certificates for a fee. These certificates will be often be shared amongst many customers. More expensive certificates are available which can be individually registered to particular web properties.
What Google says?
What each security symbol means?
Information you send or get through the site is private.
Even if you see this icon, always be careful when sharing private information. Look at the address bar to make sure you're on the site you want to visit.
ⓘ Info or Not secure
The site isn't using a private connection. Someone might be able to see or change the information you send or get through this site.
On some sites, you can visit a more secure version of the page:
Select the address bar.
Delete http://, and enter https:// instead.
If that doesn't work, contact the site owner to ask that they secure the site and your data with HTTPS.
⚠️ Not secure or Dangerous
Not secure: Proceed with caution. Something is severely wrong with the privacy of this site’s connection. Someone might be able to see the information you send or get through this site.
Dangerous: Avoid this site. If you see a full-page red warning screen, the site has been flagged as unsafe by Safe Browsing. Using the site will likely put your private information at risk.