Landlords typically do not like students as tenants. Blame the students before you that trashed carpets and broke toilets etc. So to cover the cost of having to decorate and fix things when they leave, they ask new tenants to pay deposits. You would think that is enough but, they also want you to provide someone to pay your rent if you miss a month – this is called a ‘guarantor’. Some people can’t provide a guarantor so this scheme has been set up to support such people.