Issues are the work packets in Jira Core. Each issue can be further defined by assigning the issue an issue type. For example, if you're running a project in an office, issues could represent the tasks you need to do to complete that project. Each issue type would be a type of task, like administration task, filing task, or create document task. If you're using Jira Core for asset tracking, an issue could represent an asset (or inventory item) and the issue type could be the types of assets (laptops, monitors, printers etc.). Issues then progress (or move) through Jira Core via an associated workflow that dictates what can and can't (or more correctly, what should and shouldn't!) happen to that issue.
So how do I group issues? What if I want a construction project, and I also want to track my assets for that project in Jira Core, how can I do that? Well, you use projects!
Projects are a way to group your issues, and apply a set of defaults. These defaults make sure all your issues have the information that they need to be progressed and tracked through your workflow. Each project can have an administrator, who is typically the project lead, and they're responsible for administering the project.
Jira Core users may work with issues in one or several projects, and would complete the work required to progress the issues through their workflows.
Great! You now know issues are the work, and they're grouped in projects. But what's the workflow, and how does it effect the issues?
Workflow dictates how an issue can be progressed in a project. The workflows can be as simple or as complex as you need them. Workflows are often modeled on existing processes, and are made up of statuses (or steps) and transitions (movements between statuses). When you create an issue, it will automatically be assigned a workflow and a status on that workflow. Where it can move to is defined by the transitions that exit that status. An example of the default workflow that ships with Jira Core is shown below:
Jira Core is one of several Jira applications. Each application has its own distinct features that makes it suitable for servicing the market it's designed for. For example, Jira Software is designed for agile software developers, and its features include agile boards, software specific project types, and better integration points with other developer tools.
You may have access to more than just the Jira Core application, and you can view this list of applications and feature access to gain a better understanding of the power of Jira!
So that's the basics. Jira Core is functional straight 'out of the box', but if you think you'll need to know a little more, to get some ideas on what you could do, take a look at this guide to see what's possible with Jira Core.