An Index of Multiple Deprivation (IMD) is used to identify how deprived an area is. It uses a range of economic, social and housing data to create a single deprivation score for each small area of the country. As statistics are a devolved matter, each nation of Britain handles the calculation of IMD slightly differently. The links below explain how this is done.
Scottish IMDs mapped: https://simd.scot/#/simd2020/BTTTFTT/9/-4.0000/55.9000/
How to find the Deprivation score for postcodes in England: https://imd-by-postcode.opendatacommunities.org/imd/2019