To run a bunch of Wiindows apps simultaneously, unless they are all quite small, your best bet will be to create a bootable Windows partition on your hard drive using Boot Camp Assistant, install Windows in it, and boot into Windows instead of the Mac OS when you need to run your Wndows software. Windows and your apps running in it will then have the full use of your machine's hardware.
The alternative is to install Windows into a virtual machine created by VMWare Fusion, Parallels or VirtualBox, and run Windows side-by-side with the Mac OS. But the virtual machine will have to share all the Mac's hardware resources with the Mac OS, so it may not perform as well, particularly if you run large, demanding apps in it.
Run it in a virtual machine. That way you can run both operating systems at the same time.
You will need a retail or store bought OEM version of the Windows OS you want to run and a valid license key.
I use VMware Fusion othrs use Parallels and still others use VirtualBox.
When I said a store bought OEM version I mean a OEM version you buy from places like Newgg.com. Not one that came with a branded computer like a Dell or HP or Sony or whatever other manufacturer.