Windows 10 S is Microsoft's new OS for students. The laptops that will run it -- apart from the premium Surface Laptop -- fall into two categories for their internals. One set's configuration starts with a Celeron processor, 4GB memory, 64GB storage and a sub-HD-resolution 1,366x768-pixel display. I refer to this as the "cheaper" configuration. The others incorporate more powerful Core i processors, HD (1,920x1,080) displays, and tend to be lighter. There are also a few convertibles, with 360-degree hinges, touchscreens and styluses.
The Tecra C40D is a 4-pound (1.8 kg) laptop with a Celeron CPU and a low-resolution (1,366x768) 14-inch display.
Smaller and lighter than the Tecra, the M has the same basic specs, including a Celeron and 1,366x768-resolution monitor. But in this case it's packed into an 11.6-inch display and a compact design weighing 2.7 pounds (1.2 kg).
To decrypt the product name, the ProBooks are HP's budget managed systems running Windows 10 Pro (which makes sense, since Windows 10 S is a stripped-down version of Pro). It's a convertible with a 360-degree hinge so you can use it like a tablet -- see the stylus peeking out from the left side? Same basic internal specs as the rest, but this 12.5-inch model has an HD display (1,920x1,080).
The Porteges are a more upscale line than the Tecras, and this one has a sleeker design than most of the other laptops. It also takes higher-end processors -- the Core i series -- compared to the usual Celeron and Pentiums, has a 12.5-inch, HD (1,920x1,080) display and weighs a slight 2.5 pounds (1.1 kg). They're also more expensive, though I don't have the pricing.
The Lifebook convertible has more in common with the Toshiba Portege, including higher-end Core i series, 12.5-inch HD (1,920x1,080) display and light weight of 2.8 pounds (1.3 kg). it looks like it's a little thicker, and seems to have a lot more connection options, though.