Let’s say you’ve resigned, or your boss decides it's time to part ways (nice way of saying you’ve been sacked). Usually you’d work your notice period and be on your merry way to your new job. The difference here is that on garden leave you’d go home straight away and wouldn’t work your notice. You’d do absolutely no work during that time and you’d still get paid your agreed notice. I guess you could spend that time in the garden if you fancied it