Answer: Your tree has five different branches grafted onto it, one for each variety of fruit. Over the years you will find that the plums and peach will grow faster than the apricot and nectarine so you'll need to prune those back to keep the tree looking uniform in appearance. I don't think you'll be getting fruit for another year or two so you can go ahead and prune your tree now to make it more symmetrical in appearance. As the branches grow and begin to develop fruit, you'll be able to recognize the fruiting spurs it develops (small, stubby branches coming off a main branch). For the time being, try to identify the different grafts off the main trunk so you don't accidentally prune one of the varieties off.
Best wishes with your tree!
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