Black Friday originated in America and marks the Friday following Thanksgiving. Since 1952 Thanksgiving has been unofficially seen as the start of America’s holiday season/Christmas shopping period.
Because of this, most retailers offer heavy discounts on their products, drawing consumers in to buy presents from them before Christmas.
The term “Black Friday” in the US is said to have been used as early as the 1960s, but it only really took off in the UK around 2013, when ASDA (a subsidiary of Walmart) first started advertising sales on Black Friday. In 2014 many of the UKs largest retailers followed suit, promoting Black Friday deals and huge discounts.