Batching is reserving a block of time to complete similar tasks, rather than doing them arbitrarily. You’ll be better focused and you’ll reduce the stop/start transition time.
We already do this with shopping – we create a list rather than driving to the store every time we want an apple. But most don’t think to do this with things like bills – we pay sporadically or as they come in (or the day they’re due), rather than in one 10-minute block every other week.
You’ll find you spend less time rushing if you batch email time, phone calls, reading, accounting, studying/learning, creating/writing, cooking and any other tasks worthy of your time.