Besom is an antiquated, old term that is no longer readily used (US). It seems to only have related usage as it relates to folklore or certain wedding traditions. I've never heard it in any modern usage. General purpose word is 'broom' although maybe in some places, older people might refer to it as a 'sweeper.'

I've never heard the word besom before. I looked it up and it looks like besom refers to a broom made of twigs tied around a stick. A broom might use plastic bristles, but it sounds like a besom doesn't. I would suggest not using besom unless you have a very specific reason.