If your Sky Q main box is displaying at a resolution of 2160p (which is also known as 4K or Ultra HD), then yes, it's capable of delivering high-resolution content. Sky Q supports 4K content for certain channels and on-demand services, provided you have a compatible TV and a subscription that includes 4K content.
For standard HD content, the resolution is typically 1080p (Full HD). If you're watching HD content, it usually will not come in at