WCS is only if you want to manage multiple WLC and yes you don't need it. The WLC is the device that will communicate with the LWAP and make management soooo much better for you. Hope this short statement helps.
Just to add, WCS is software that you install on a server whereas WLC is a physical box. Each WLC can be managed individually through a Web interface by connecting to the management interface using http or https. If you only have one two controllers chances are you won't need WCS. WCS becomes handy if you have enterprise with many WLCs and possibly location devices.