Workstation includes Player, but the best way to decide might be to get the Workstation trial. Use it for the demo period, and then decide if you want all of the functionality it offers or if you can live with Player. Player is free and will continue to work after your 30 day Workstation demo is up.
Installing one of these products allows you to create a lab environment on your laptop. If you could only install ESXi on your laptop, then you could only use it for that and you can't really interact with VMs in a meaningful way from the DCUI or ESXi Shell on that console. Using one of the hosted products (Player, Workstation) allows you to have the laptop's OS as well as a virtual lab with ESXi, vCenter, etc. Again, I think that building your own lab using these products will enhance your overall knowledge of virtualization. The abstraction is greater, and this requires you to think/learn more in the process.