All What You Should Know about "SSL Certificate"

An SSL certificate is a digital computer file (or small piece of code) that has two specific functions:

Authentication and Verification: The SSL certificate has information about the authenticity of certain details regarding the identity of a person, business or website, which it will display to visitors on your website when they click on the browser’s padlock symbol or trust mark (e.g., the Norton Secured Seal).
The vetting criteria used by Certificate Authorities to determine if an #SSL certificate should be issued is most stringent with an Extended Validation (EV) SSL certificate; making it the most trusted SSL certificate available.

Data Encryption: The SSL certificate also enables
encryption, which means that the sensitive
information exchanged via the website cannot be
intercepted and read by anyone other than the
intended recipient.
In the same way that a identity document or
passport may only be issued by the country’s
government officials, an SSL certificate is most
reliable when issued by a trusted Certificate Authority
(CA). The CA has to follow very strict rules and
policies about who may or may not receive an SSL
certificate. When you have a valid SSL certificate
from a trusted CA, there is a higher degree of trust
by your customers, clients or partners.
Further if you are curious to know more about the
SSL, below is the link of answer which can be helpful
to you.

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