Ferrous and non-ferrous metals are two different types of metals. This categorization is based on the iron content. In case the metal contains iron, it is known as a ferrous metal, otherwise as non-ferrous metal.

Both, Ice and Dry Ice are used for their cooling properties. The key differences between ice and dry ice lie in their chemical structures, properties and their contradictory temperatures.

Water Cycle or Hydrologic Cycle or the H2O cycle describes the continuous movement of water from on, above and below the surface of Earth. It is the journey, which water takes as it circulates from the land to sky and back again. This cycle maintains the water consistency throughout the Earth.

Dissolution is the process through which a solute gets dissolved into a solvent and forms a solution. Solubility is a quantitative term defining the maximum amount of solute which gets dissolved into the solvent.

In calculus, differentiation is the process by which rate of change of a curve is determined. Integration is just the opposite of differentiation. It sums up all small area lying under a curve and finds out the total area.

Seedling and sapling are two different juvenile life stages of a tree. Seedling refers to a very young tree which is less than 1 inch in context to DBH. Stage of seedling is followed by the stage of sapling which is generally 1 to 6 inches in context to DBH.

An alloy is a blend consisting of metal and other elements. Alloys are generally made for achieving properties like greater strength or resistance to corrosion. Steel is an alloy of iron. It mainly consists of iron with some small amounts of carbon.

An alloy is a metallic substance made by combination of metal with other types of elements. It is generally done in order to enhance properties like strength, ductility, corrosion resistance, etc. An ore is a natural source of mineral from which metals are extracted in order to gain profitability.

Arithmetic and Algebra are two branches of Mathematics. Arithmetic, being the most basic of all branches of mathematics, deals with the basic computation of numbers by using operations like addition, multiplication, division and subtraction. On the other hand, Algebra uses numbers and variables for solving problems. It is based on application of generalized rules for problem solving.

Perennial rivers are those rivers which exhibit a continuous flow of water throughout the year except during extreme drought. On the other hand, non-perennial rivers are those rivers which have no flow for at least a part of the year.

Gyroscope is used for the measurement of angular rotational velocity whereas the accelerometer is able to measure linear acceleration of movement.

Delta is a sedimentary deposit formed at mouth of some rivers. It is usually triangular in shape. On the other hand, an estuary is a semi-enclosed body of water where fresh water meets the ocean.

Absorption is a bulk phenomenon in which absorbate completely penetrates into the body of a solid or liquid to form a compound or a solution. On the other hand, adsorption is a surface phenomenon in which molecules of an adsorbate concentrates only on the surface of adsorbent.