An SSL is essential to protect your clients' confidential information, such as credit card data and social security numbers. Many of your visitors will not complete an online data form without verifying that protection is provided by a valid SSL certificate.
SSL stands for "Secure Sockets Layer". Used by most commerce servers on the World Wide Web, this high-level security protocol protects the confidentiality and security of data while it is being transmitted through the internet. Based on RSA Data Security's public-key cryptography, SSL is an open protocol that is the online industry security standard.