* Photo- refers to light (specifically sunlight).

* Auto- means self.

* Troph- relates to nourishment.

So, photoautotrophs are organisms that make their own food using light energy from the sun. The most common examples are:

* Plants: They use photosynthesis to convert sunlight, water, and carbon dioxide into glucose (a type of sugar) and oxygen.

* Algae: These single-celled or multicellular organisms also use photosynthesis, contributing significantly to the Earth's oxygen supply.

* Cyanobacteria: These bacteria also use photosynthesis and are a key part of many ecosystems.

It's important to remember that these organisms are at the base of many food chains. They are the primary producers, meaning they convert sunlight into usable energy for other organisms.