Those granted refugee status or humanitarian protection, including those who are resettled to the UK, have the right to work here without any restrictions. There is guidance available on Gov.UK that provides information about the help that refugees can receive to find work, and the benefits to which they are entitled: https://www.gov.uk/government/publications/refugees-guidance-about-benefits-and-pensions/help-available-from-the-department-for-work-and-pensions-for-people-who-have-been-granted-leave-to-remain-in-the-uk.
Where applicable, employers can check whether an individual has the right to work using the Employer Checking Service. Guidance on using this service can be found on Gov.UK here: https://www.gov.uk/check-job-applicant-right-to-work.
Asylum seekers are not allowed to work in the UK unless their claim has been outstanding for at least 12 months through no fault of their own. Those who are allowed to work are restricted to jobs on the Shortage Occupation List. This is made clear on Gov.UK at: https://www.gov.uk/claim-asylum.