As @Rups noted it’s a payment to people with disability. What he hasn’t included in his very brief explanation is 1) It’s non means tested!!! Payment is a right if you qualify from the point of view of having a disability that removed your abilities to some normal activities such as preparing a food, personal hygiene and dressing unassisted
2) the form is quite a challenge often rejected and then you have to appeal which is an absolute right as is right to a tribunal at third attempt
3) the government is trying to phase it out as an expensive demand on resources ( It’s changed its name in Scotland to Disability Living Allowance)
There is a post on it and many other benefits
Caio
Simon