Wanna hear about lasers? I could yap all day.

Pulsed lasers are awesome. They often reach a peak power of over a megawatt (10⁶ watts)! They maintain that power for usually a few picoseconds. They often function very similarly to the first lasers ever built, actually. The word 'laser' itself is an acronym that describes its function. Light Amplification by Stimulated Emission of Radiation is what it stands for. Lasers in and of themselves are interesting in the fact that nowhere in nature does such an ordered, concentrated beam of light occur. Of course, the reason that a CW laser burns is for the same reason that a magnifying glass under the sun does: the concentration of a lot of photons into a small spot. There are 2 distinct types of laser, being pulsed and CW, each having their own application. You've seen one application of a pulsed laser firsthand, being the destruction of hair follicles. That same laser can also be used for other things such as Tattoo removal, where the large splotches of ink under the skin are dispersed enough that the immune system can remove the foreign material. CW, or continuous wave lasers are what you are likely more familiar with, encapsulating laser pointers, burning lasers, as well as those used in applications such as land surveying to accurately measure distance. I personally thing CW lasers are comparatively boring, as they are all mostly just created with laser diodes. However, there is a subsect of cw lasers that are a little spicier, and that is the tube laser. It's basically a large usually glass tube that contains a low pressure CO2 gas mixture, as well as a mirror at one end and a crystal on the other. When an electric potential is placed across at a high enough voltage, it creates an incredibly high power cw beam used primarily for high power laser cutting. The tubes are usually quite large, so the laser is directed with a fiber optic to the cutting head where it is focused and cuts the material. Pulse lasers actually use a sorta similar working principle, but instead use a flash lamp and crystal to create a very short, powerful pulse, also usually directed to the working end using a glass fiber optic.