In the new Windows I have a question on how to stop windows from maximizing?

I just got a new computer and operating system. I'm still getting used to the new layout that Windows came up with. I am a multitasker and often have two or three small windows open, pulling information from one to add into a spreadsheet open in another. I need to move the smaller windows around and am getting super frustrated with the new set up because if you take a small window and move it too close to the edge of the screen, it maximizes! How do I stop it from doing this? I want to be able to put a reduced window near the edge of the screen without it changing sizes....