Jira is a project management tool developed by Atlassian. It was first launched in 2002 as an issue tracking system, but now encompasses several key processes in agile project development.
Jira comes in three suites:
Jira Core is a basic project management platform for non-technical teams. This can be used to plan, track, and report on work across multiple departments.
Jira Software is another general project management platform, but this time geared towards software development teams. It's used for tracking bugs, adding new features, and assigning/following tasks.
Jira Service Desk is an add-on to the versions above. Jira Service Desk is centered around customer support, acting as a platform for IT, customer support, and help desk agents. It also offers features like ticket tracking and incident management.