Why do british people call french fries chips?

The origins of the word "chips" referring to french fries can be traced back to 19th century Britain, where the word "chip" was used to refer to a long, thin slice of potato that was fried. These thin, fried potato slices were then referred to as "french fries" in the United States, named after the French who were known to have been frying potatoes in thin strips.

The term "chips" for fried potato sticks gained popularity in Britain and eventually became the more common name for french fries in the UK, Ireland and New Zealand.