When you are submitting a new request the first question you are asked will be the issue type, this is used to help direct your issue to the right team so it is important the correct issue type is selected. Below are the 3 different of issue you can select from, and when to use them.
Incident/Issue/Bug
An incident/issue/bug should be used when something is not working as it should, this could be a page on a website not loading, or an application is giving you an error message when you try to do something.
New Development
A new development change request should be used when you want an application or website to do something different to what it currently does, this maybe adding an extra set to an existing process or adding brand new functionality.
Service Request/General Query
A service request should be used for general tasks such as setting up a new user, asking for a report or data export (note a lot of the Linney systems do allow you to manage many of these tasks yourself so please always check the articles on the Help Centre to see if this is something you can do yourself before submitting a new request).