Jira Service Desk
Apart from business teams and software teams, Jira Service Desk targets support desks or help desks.
In Jira Service Desk, there are the standard features of a service desk tool such as a customer portal to raise tickets and search in the knowledge base for self-serve for customers; for the agents who will be handling the tickets, they have configurable queues. Just like Jira Software, Jira Service Desk also contains all of the features and benefits of Jira Core.
As you must have already guessed, Jira Core is the most basic tool and, based on your requirements and whether you want to develop software using Agile methodologies, the waterfall methodology, or a custom development process, you can use Jira Software. For providing support to your customers and handling tickets in Jira, you can use Jira Service Desk.