Can someone explain me when I need a web site certificate?I will have a web app that will be used for representing live data. Do I need a certificate for that type of web application? A user will be allowed to enter some new records in the database and make queries.If the answer is yes, then can you provide me with some cheap options as this is a new expense for me which I haven't thought of. 
When do I need a website certificate?
security certificate;web applications
You need a website certificate when you need to protect your user's data against eavesdropping in transit. To protect against this, people typically use HTTPS instead of HTTP. For HTTPS the server presents a certificate to the client, the client decides whether to trust that the server is who it claims to be by checking that the certificate has been signed by one of the certifying authorities whose signature is known to the client.Unless you are passing back and forth data that is personal or confidential, you don't need this.