These compounds are all forms of iron and its compounds, with varying oxidation states. Let's break it down:

Fe - This is the chemical symbol for elemental iron, which is a metal found naturally in the Earth's crust.

FeCl2 - This is iron(II) chloride, a compound where iron has an oxidation state of +2.

Fe(OH)2 - This is iron(II) hydroxide, which is a solid that can be produced by reacting iron(II) salts with hydroxide ions.

FeO - This is iron(II) oxide, also known as ferrous oxide or wüstite. It is a black solid that is often used in magnetic materials.

FeCl3 - This is iron(III) chloride, a compound where iron has an oxidation state of +3. It is commonly used as a catalyst in organic reactions.

Fe(OH)3 - This is iron(III) hydroxide, a chemical compound that can be formed by reacting iron salts with hydroxide ions.

Fe2(SO4)3 - This is iron(III) sulfate, a compound where iron has an oxidation state of +3. It is a commonly used chemical compound in various industrial processes.

Overall, these compounds represent the different oxidation states of iron and its reactivity with different elements and ions.