Issue tracking systems keep track of issues, bugs, and other tasks. The first issue tracking systems were created to maintain the list of bugs and also the state of the bug fixing process to ensure that a bug, identified and recorded, will not get forgotten. Later, these software solutions developed and became full-fledged issue trackers and are unavoidable project management tools in every enterprise.

The most widely used issue tracking application used in many enterprises is Jira, but on the https://en.wikipedia.org/wiki/Comparison_of_issue-tracking_systems page, you can find many other applications listed.

The most important feature of an issue tracker application is that it has to record an issue in detail in an editable manner. It has to record the person who recorded the issue in case more information is needed during issue handling. The source of the issue is important. Similarly, issues have to be assigned to some responsible person, who is accountable for the progress of issue handling.

Modern issue tracking systems provide complex access control, workflow management, relation management, and integration with other systems.

Access control will only allow the person who has something to do with an issue access to it, so others cannot alter the state of an issue or even read the information attached to it.

An issue may go through different workflow steps depending on the type of issue: a bug may be reported or reproduced, a root cause analyzed, a fix developed or tested, a patch created, a fix merged with the next release version or published in the release. This is a simple workflow with a few states.

Relation management allows setting different relations between issues and allowing the user to navigate from issue to issue along these relations. For example, a client reports a bug, and the bug is identified as being the same as another already fixed. In such a case, it would be insane to go through the original workflow and creating a new patch for the same bug. Instead, the issue gets a relation pointing to the original issue and sets the state to be closed.

Integration with other systems is also useful to keep a consistent development state. Version control may require that, for every commit, the commit message contains a reference to the issue that describes the requirement, bug, or change that the code modification supports. Issues may be linked to knowledge base articles or agile project management software tools using web links.