A switch is essentially redeeming one fund and purchasing another within the same AMC.
So for example, you are invested in a small cap fund, you think the market has run up, you can switch from this to a debt fund. This can be done only regular/online funds with a click of a button.
Currently on Coin, you will have to redeem, wait for the proceeds and the repurchase the other fund. No direct switch button is available as these are direct MF held in demat form which is being transacted using the exchange platform. (So works like stocks).
Switch is a capital gain event whatever way you do it - either hit the switch button or redeem and invest. Since you are exiting, the profits will be taxable as capital gains.