I will try, although it's not easy without visual aids.
The VOR receiver integrates the signal from the beacon with a heading input and deduces which radial it's on. It can work this out regardless of the aircraft attitude. The ADF is a dumb gadget and just points at the beacon. If you're wings level and the beacon is 45 degrees from the nose, it will point 45 degrees off the index. But imagine you are in a 30 degree turn towards the beacon. The relative bearing reduces.
Can't imagine that, well now bank to 90 degrees. The relative bearing of the beacon is now on the nose and you are apparently pointing straight at it.
Still not got it? Well, take your coffee mug off the coaster and place it to the right of the desk. Pick up the coaster and hold it level above your desk. This is your aircraft. Now pick up your biro and place it on the coaster pointing at the coffee mug (the beacon). Now bank the coaster towrds the mug while keeping the biro pointing at the mug. What happens? You should notice the biro turning towards the nose of the aircraft and the relative bearing reducing. Now expalin to your wife how you got the hot drink ring on the desk.
The next question to ask is why we are using stone age navaids in this age of inertial reference systems and GPS.