SSL secure socket layer provides security to the data that is transferred between a web browser and the server. It is an encryption-based internet security protocol.
In other, we can say that SSL and its successor Transport layer security [TLS] are protocols for establishing authenticated and encrypted links between network computers.
A website that implements SSL/TLS has HTTPS in its URL instead of HTTP.

Types of SSL [Secure Socket Layer]:

Single Domain Certificate: It applies to one domain and one domain only. It can’t be used to authenticate any other domain not even the domain it is issued for. It can secure a single subdomain, hostname, IP address, or mail server. This variation is available in DV, OV, and EV authentication options.

Wildcard Certificate: It applies to a single domain and all its sub-domains. Users can see a list of subdomains covered by a particular certificate by clicking on the Padlock in the URL of their browser. This type offer full encryption for the subdomains making it an affordable and effective solution for most website. they are available in DV, OV, and EV validation options.
Multi-Domain Certificate: MDC or it is also called Subject Alternative Names [SAN]. It can list multiple distinct domains on one certificate, with an MDC, domains that are not subdomains of each other can share a certificate. One of these can secure up to 250 unique domains with a single solution. This certificate is available in DV, OV, and EV options.

SSL Validation Types :

Domain Validation [DV]: The certificate authority [CA] checks the right of the applicant to use a specific domain name. no company identity information is vetted or displayed other than encryption information without a secure site seal. DV SSL Certificates are fully supported and share the same browser recognition with OV SSL, but we do not need to submit company paperwork.

Organisation Validation [OV]: The CA checks the right of the applicant to use a specific domain name plus it conducts some vetting of the organization. The organization name also appears in the certificate under the field.

Extended Validation [EV]: It involves the full background check of the organization. The CA will make sure that the organization exist and is legally registered as a business that they actually are present at the address they listed and so on. They are more trustworthy than other types of SSL certificates.

Easy to Install: SSL does not require the installation of client Software. The only thing required is to connect to the internet through a standard web browser. To install a SSL Certificate no need for professional guidance is required.

SEO: SSL Certificate is one of the factors to boost search engine rankings. The effect of the algorithm can be clearly seen in the fluctuations in the SERP [ Search Engine Ranking Pages ] ranking.

Security: The main goal of an SSL Certificate is to encrypt information so that it can only be read by intended recipients. SSL converts the data into some unreadable code and format that can be accessed and used by authorized ones.

Secure Customer Payments: All the payment card industries require sites to have an SSL Certificate with at least 128 bits of encryption to accept payments without a proper SSL certificate sites won’t be able to accept payment with credit cards.

Cost: Purchasing and setting up of SSL Certificates can be quite expensive which is basically due to the maintenance and verification protocols. If you want multi-domain certificate which cover domain and subdomain obviously the cost of SSL is much more than the single domain. Therefore the cost of SSL is considered the major disadvantage of SSL.

Performance: When use SSL Certificate is used on a site, the speed of transactions will get drastically reduced. This is because of encryption and decryption of data before it can be used.

Expiry and Renewal SSL: The SSL Certificate needs to be renewed and updated periodically especially, every year. If not updated the SSL stops hence the customer can lose trust while conducting transactions.

Coaching Issues: Encrypted data will have a problem with coaching if the proxy coaching system that is set up on the web browser is complex. Therefore to deal with this encryption additional servers are placed just after the encryption reaches the coaching server and hence the data is properly encrypted and presented to the destination.

It is used to protect data from being stolen, changed, or compromised and works by scrambling data into a secret code that can only be unlocked with a unique digital key.
Also, we can say it is the process of using a code to transform plain text to cipher to ensure that sensitive data remains unreadable to an unauthorized user.
It is very essential for ensuring the trusted delivery and storage of sensitive formations.

It is a technique that simply means the conversion or transforming of encrypted data into its original form is called Decryption.
It is generally a reverse process of encryption.

Note: Encryption is useless without Decryption and vice versa.