Boolean Logic

In this article, the basics of Boolean Logic is explained

Boolean Logic
Boolean Logic

Boolean Logic or Boolean Algebra is the description of a set of objects using two basic logic’s – TRUE & FALSE. The relation between these two logics is used to figure out the truth of an expression. Boolean Logic is considered to be the basic of digital electronics. We know that a computer’s most basic operation is based on digital electronics. Thus a True logic is considered as a digital 1 and a False logic is considered as a digital 0.

In school based algebra, the values of variables are numbers, and the operations on these numbers are carried out using simple addition, multiplication, division and subtraction operations. But, in Boolean algebra, the variables are values to be True or False, instead of numbers and the operations are logical.

Earlier, there were operations which only humans could do. But now, these operations [and maybe more] can be done by computers. With the addition of certain operators (AND, OR, NOT) between the True and False logic’s, you can describe the relationship between them. The Boolean Logic was first introduced by George Boole during the 1800’s. He performed his concept with the help of simple logical instructions. He was able to successfully convert formal logic into a precise mathematical form. In Boolean logic, an expression has only one output – either True or False. Such an exclusive output condition is known as “the law of excluded middle”.

Now let us evaluate a Boolean condition through an example: – Snowy_day.

This condition could either be true or false.

Now let’s say you want to go skiing in this weather. But you have to make sure that it is not sunny or raining. Thus, you can use the Boolean logic to sort this problem.

If (Snowy_day) THEN…

Now let’s say you need a helmet as well while skiing, for safety. Thus, add the new variable Helmet.

If (Snowy_day) AND (Helmet) THEN

The AND condition used here indicates that if both the conditions are true, then you can go out skiing. If either one of the condition is false, you stay home!!

The same condition would have a different output if an OR operator was used instead of AND.

The basic Boolean operation can be further mapped into operations using bits and bytes. The most basic idea of Boolean Logic can be explained using logic gates.  When the logic required becomes complex, these logic gates can be combined into more complex forms to get the required output.


Search Engine

The most common application of Boolean logic is the search engines in the internet. There are search engine websites that allow us to implement Boolean logic The search engine application can be explained with an example:-

Suppose you do an image search for the famous cartoon character “DONALD DUCK”.

You could have the same keyword searched in different formats like “Donald”, “Duck” or “Donald Duck”. Either way the search result will vary according to each keyword. By the use of Boolean operator AND for the search “Donald AND Duck”, you get the perfect search result of the cartoon character. This is the application of Boolean logic explained in the most basic form. But the logic gets complex and isn’t that easy to grasp. Other than the “AND” opeartor and the “OR” operator there are many more operators with specific logical conditions and outputs. Please go through the article Logic Gates to get a better idea.

Other Applications

The games that we play in our computers like chess and solitaire, and even the use of Word Pad for typing documents is an application of Boolean Logic. These ideas of Boolean Logic are implemented in semiconductor chips made out of silicon and also with the help of external connecting wires. These chips do exactly whatever instructions are fed into it, and that too without a single mistake.

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  1. excellent source of information for boolean logic. really helped me with a school project.