In ServiceNow, there are several types of tickets used to manage and track various kinds of requests and issues within an organization. These tickets are essential components of the IT Service Management (ITSM) process. The primary types of tickets in ServiceNow include:

1. Incident Tickets: These are used to track and resolve unplanned interruptions or reductions in quality of IT services. Incident management focuses on restoring normal service operation as quickly as possible to minimize impact on business operations.

2. Problem Tickets: When multiple incidents reveal underlying flaws in the IT infrastructure, problem tickets are used. Problem management aims to identify and remove these underlying causes, preventing recurrence of incidents.

3. Change Requests: These tickets are for managing changes in the IT infrastructure. They are used to assess, approve, and implement changes in a controlled manner to avoid unintended service disruptions.

4. Service Requests: These are requests from users for information, advice, standard changes, or access to services. Examples include requesting a new workstation, access to applications, or information about how to use a particular IT service.

5. Task Tickets: In some ServiceNow configurations, tasks are used as part of managing workflows. A task ticket can be part of an incident, problem, change, or service request. It represents a piece of work that needs to be done.

6. Knowledge Articles: While not a ticket type per se, knowledge articles in ServiceNow are used to provide users with information on common issues or questions, potentially reducing the number of tickets raised.