I know that all 3 activity has nearly same purpose.
1.element exist gives bolean output.it check for element for certain amount of time (30 sec default timeout) and took feather action acc. to the output.
2.On element Appear: wait the element to appear (timeout for waiting). if found then take next action. if not found then i guess it give error.
3.Find element : it gives Ui element as output. and we can check if uielement output is nothing or not for futher action.
On my point of view this three activity are similar. So can anyone help me for best practice or scenario when to use which activity
Can anyone please share more detais. please correct me if i am wrong