Your laptop was built to consume less power than its desktop computer cousin. The laptop uses a special processor that draws less power and produces less heat. Everything inside the laptop case is geared toward battery savings. Even so, they do draw power.
Here’s the short list of items that consume the most power in a laptop:
The screen
The hard drive
The optical drive
The audio system (speakers)
The dial-up modem
The wireless network interface
The (wired) network interface
The Bluetooth radio
What else? Peripherals! If you plug a USB anything into a laptop, it draws power. Major culprits are external hard drives and mice.
All the items listed above consume power when in use, especially the screen and even more so for a touchscreen display. By not using these devices, or by rationing their use, you can save power.
Many of these power-hogs are governed by using power management tools in Windows: The display can be dimmed, hard drives un-spun, and other features disabled or run in a low-power mode.
