How does a parabola help concentrate or transfer energy/heat?

Why do we use parabolas? Why is that shape used instead of something else? What is the "focus" of a parabola, and what does it do?

Why are parabolas useful and important?

PINAR ASLAN-SALİHLİ ŞAHİN ŞEN GİRLS ANATOLİAN IMAM HATİP HIGH SCHOOL

https://cleanleap.com/1-parabolic-trough/how-doe-supports-parabolic-trough-technologies

THIS PICTURE SHOWS HOW THE PARABOL IS USED IN ENERGY AND HEAT PRODUCTION.

Berfin Aslan Şehit Fatih YENİAY Anatolian High School.

Parabolic (reflex) solar concentrators. Unlike refractory, reflex concentrators work on the principle of collecting the reflected sunlight into the energy beam. By their design, they are divided into flat, parabolic and parabolic cylinders. If we talk about the effectiveness of each of these types, the highest degree of concentration - up to 10000 - gives parabolic condensers.

Necmiye Doğruyol

Şehit Fatih YENİAY Anatolian High School:

Parabola in Heat Production

Parabolic Reflectors and Solar Energy

Özlem Kahraman / Babaeski Şehit Ersan Yenici Anadolu Lisesi

Solar heaters and other parabolic devices

 GÖRELE ANATOLIAN HIGH SCHOOL -EMRE ARDA

Parabolic mirror surfaces are found wherever energy needs to be focused efficiently and accurately. You find them built into car headlights, spotlights as well as astronomical telescopes. Here we explore the parabola to design solar heaters. 

Photo 1. Two photos of a small solar heater made from plastic mirror sheet bent into a parabola shape by a wooden template. There is a black temperature data logger at the focus which is where the solar energy is being concentrated. Apart from the screws and plastic mirror all the parabola 'bits' were made from scrap

What to heat?
At the equator there is about 1kW of solar power for every square meter of collecting surface. The small heater shown in photo 1 only has an area of about 1/20th m² but it still makes a good demonstration. Larger parabolic system having say 1-2 m² surface area should have enough energy to boil water in a small kettle for a cup of tea! The amount of heating obviously depends on the time of year / day, the weather and 'strength' of the sun (your latitude). Painting the kettle mat black with fire proof paint helps. Putting a large transparent plastic bag around the kettle also helps reduce heat loss (it acts like a mini green house). It would be fun to try cooking an egg on a flat plate arranged at the focus.

İZMİT MEHMET AKİF ERSOY KIZ ANADOLU İMAM HATİP LİSESİ

https://www.sciencedirect.com/topics/engineering/parabolic-dish