Oxidation vs Combustion
We have heard of the process of combustion and oxidation in our school. But only a few know about the main differences between them. In combustion organic compounds are completely burnt and get oxidized to CO2 and water. The process needs oxygen to occur. However in oxidation, oxygen is added to the compound. In case of oxidizing the element, we can say that an ion of negative charge has been lost or an atom is lost from the element.

Whenever combustion takes place oxidation is the end result, but it is not the same for oxidation. Combustion is accompanied with exothermic reactions which happen after a series of complex chemical reactions. It involves an oxidant that is required to catapult the experiment. Heat and light are also produced during the reaction. On the other hand in oxidation, oxygen is gained and hydrogen molecules or the electrons are lost thereby giving the element or the compound an oxidized form.

What happens in combustion? In this process the compound reacts with the element that acts like an oxidizing element (for example oxygen or fluorine). The end substance obtained consists of compounds which also have the oxidizing element as part of their chemistry. What is the procedure of oxidation? In oxidation the oxidation state of the compound is changed by two processes:

Redox process: For example oxidation of carbon to CO2.
Reducing the element of carbon to obtain CH4, also known as methane by the help of hydrogen.
This can also be represented by the example of sugar oxidation that takes place within the human body. This process involves a series of very complex process that includes electron transfers within the cell structure.

There may be different types of combustion processes like rapid combustion, complete combustion and incomplete combustion. We can define oxidation as a process in which oxygen reacts with the substances that come in its contact and form substances which have different properties. For example, iron or Fe gets converted to Fe3O4 when oxygen reacts with it. This is also termed as rusting that occurs in our day to day life. Oxidation can take place in case of living organisms too.

Combustion takes place in the liquid fuels that you burn in your vehicles. This process takes place in an atmosphere where oxygen is available and the entire reaction takes place in a gas phase.

Summary:
1. In combustion process organic compounds are oxidized in carbon and H2O molecules. The process requires oxygen participation. Whereas in oxidation, an ion is lost by the addition of oxygen.
2. In combustion, oxidation is the end process but same is not true for the oxidation process.
3. In combustion heat and light are produced but this is not the same with the oxidation.