SSL provides security for data sent to and from a web site.
Technically speaking, SSL (Secure Sockets Layer) is the accepted protocol used to protect data that is sent between a web site and a web browser. An encrypted SSL connection requires that all data passed between the browser and the web site server be encrypted by the sender and decrypted by the receiver. SSL can prevent unauthorized parties from gaining access to sensitive, confidential, or personal information such as a phone numbers or addresses.
Why is SSL useful? Secure connections become very important when you're gathering information from your site's visitors through a web form. By placing the form in a secure directory, the form data will be encrypted when the user submits the form, thus protecting the data and your visitor's personal information.
SSL also provides peace of mind to web site visitors. When an SSL-enabled connection is established in a web browser, the user will see a lock icon in his browser, indicating that any data transferred between the web site and the browser is secure. Most web users demand this protection when shopping online or submitting sensitive data in a form