An SSL certificate encrypts data sent from your user’s computer sent to and from your website / server. It helps prevent other people or programs from stealing the information while information is passed from one side to the other.
If you have an eCommerce site, where customers and clients are putting in their credit card details, you really must have an SSL certificate. For starters, people who see a checkout page that’s not secured with an SSL certificate are more likely to abandon their cart. The opposite applies – SSL certificates build additional trust with potential shoppers – verifying that you are a real business and giving them the confidence to know that their credit card details are safe when making the transaction.
SSL certificates are also just good practice. Some of our clients have SSL certificates on their contact forms. This is to a) help build more trust and confidence with the user and b) to secure the data being sent from the user’s computer to their server – to prevent spying/stealing confidential information the user is entrusting you with by writing and sending it to you.