First let us look at what DNA is. DNA is a microscopic structure that we find inside our cells. Most of it is found inside the nucleus of our cells but some of it is found outside the nucleus too.
Structurally, DNA is a strand-like material made up of building blocks called base pairs. The arrangement of these base pairs is identical in every cell of our body. This means that all the DNA in our cells are identical to each other.
And this arrangement of base pairs is also unique for each and every individual. The uniqueness of the DNA and its identical arrangement in the cells of a given individual makes it possible to identify someone using his or her DNA.
The DNA test is nothing but analyzing and establishing a record of the DNA of an individual. This is done in specialized DNA labs using highly sophisticated technology.
The record of the DNA of an individual will be the same no matter how many times DNA is tested and no matter what sample is used to extract the DNA out. Comparing and matching the records of analysis of two DNA samples thus allows an infallible method of identifying someone.
Because our DNA is something we inherit from our parents, our DNA will have certain similarities which are comparable to that of our parents' DNA. Our grandparents' DNA which will be passed onto us from our parents will also have some similarities to our DNA. In this way our relations and our ancestors can be determined or traced. This is what some of the DNA testing laboratories use when they trace our family tree. This is also the principle applied when DNA is tested to establish paternity.
So, in short, the DNA test is a test which can determine the individual identity of a person with an extremely high degree of accuracy.
