When it comes to dishwashers, there is no one-size-fits-all answer to the question of how much clearance you need on either side. The amount of space you'll need will depend on the specific model and make of dishwasher you have, as well as the layout of your kitchen.
That said, most dishwashers require at least a few inches of clearance on each side in order to function properly. This is typically so that the door can open and close without hitting anything, and also so that water can drain properly during the wash cycle.
If you're unsure about how much space your particular dishwasher needs, it's always best to consult the manufacturer's instructions or reach out to a professional for help. With a little bit of planning and forethought, you can ensure that your dishwasher has all the clearance it needs to run smoothly for years to come.