Hi I am bit confused with the term project. Right now i am working as a project Manager in a startup firm where we have one prime client with a full time dedicated work and our product is an online event management website. This website is a huge product in itself and spans across multiple components/modules like search, payments, profiles etc. So now i have just started using Jira and i want to know should i consider each component/module as an individual project? Or there should be one project and those modules should be considered as an epic. Another point to consider here is that many of those modules are already build and tasks/features keep coming into them. So should I consider them as components in JIRA? If I consider them as Epic then there might be a situation where I won't be able to close that epic ever. But the plus side I can manage it from my single project. And can I say this hierarchy is correct?
Product-->Project-->Epics-->Story
And can we have a single backlog for multiple projects if we opt for that option? Please help me I am very confused.