By default, you will be logged out of the CRM system after 2 hours of no activity. This is a security feature so that if you leave your workstation unattended nobody else will be able to access your data.
However, your Administrator can override this by ticking the checkbox at the bottom of the Company Settings page.
Users can select to ‘Keep me logged in’ on the login page and this will keep them logged in continuously for two weeks or until they logout.
