**1. Introduction**

Every time you hit the search button on Google, the search engine sifts through thousands of searches, if not millions of web pages, to spit out the content we are seeking in a fraction of a second. It is an algorithm – a set of mathematical rules embedded in the software, which makes all this possible. In fact, every time we enlist for a unique identity social security/Aadhaar number, access an automated teller machine, book train or air tickets, or buy merchandise online, we are indirectly expanding the scope and range of algorithms, a mathematical concept whose roots date back to 600 AD with the invention of the decimal system.

Algorithms are nothing but the logically group of instructions aimed at solving a problem or completing a task. Recipes are algorithms like math equations. Computer code is algorithmic. Algorithms are aimed at optimizing everything. Mathematical algorithms include fundamental methods from arithmetic and numerical analysis, which in turn manipulate the data through addition, multiplication of integers, polynomials, and matrices, and may be used for solving a large variety of mathematical problems which arise in many contexts: solution of simultaneous equations, data fitting and integration, and random number generation. Here, the main emphasis is on algorithmic aspects of the methods, rather than the mathematical basis.

Whenever we use a computer, laptop, phone, or a mileage calculator in a car, we are using algorithms, and we may call it programs, or software packages, or apps. They can make things easier, save lives, and surmount disorder. To discuss the effects of technology-enabled assistance in human lives, algorithms are a useful artifact to begin with. Algorithms have penetrated in every aspect of human life and provide a better standard against which to compare human cognition itself. It becomes the new arbiters of human decision-making in almost any area we can imagine like which movie to watch to which house to buy to self-driving cars. Biometrics refer to identifying human being by certain physical features like fingerprints or iris scans. Biometrics-based social security identity card or Aadhaar card, in Indian context which evolved as the India's universal identity card, in turn uses an algorithm to store and retrieve fingerprints and iris scans. Computer scientists have devised algorithms that can analyze a given thumbprint and match it against a database. Because of the overdependence of human beings on computer, indirectly only the algorithms determine whether one gets a job or one get into college or get an apartment; moreover, their work goes largely unnoticed. Algorithms are behind many routines works, but they are still significant decision-making tools in everyone's life.

Deloitte Global predicted that, in time to come, more than 80% of the world's largest software enterprise companies will have cognitive technologies, mediated by algorithms integrated into their products. Algorithms with the perseverance and ubiquity of insects shall automate the processes that are used to require human intervention and rational. These can now achieve basic processes of measuring, monitoring, seeing, or even counting. Our vehicle can guide us where to slow down. Our television sets can now advocate which movies to watch. A grocery can recommend a healthy amalgamation of foods and vegetables for lunch/dinner. Alexa/Siri reminds us important events or anniversaries of dear ones. The overall impact of pervasive algorithms is very hard to calculate because the presence of algorithms in every walk of life, everyday processes, and transactions is now so great and is mostly hidden from public view.

Algorithms are making enormously significant pronouncements in our society in almost every walk of life, ranging from welfare benefits to medicine to transportation to criminal justice and beyond. The ever-increasing assortment and investigation of data and the resulting application of this information can decrease poverty, cure diseases effectively, bring apt resolutions to mankind, places where need is utmost, and dispel epochs of prejudgment, illogical suppositions, vicious practice, and obliviousness of all kinds. Algorithms are now redefining how we think, what we know, and what we think. Algorithms are a black box and are invisible pieces of code that tell a computer how to accomplish a specific task. An algorithm directs the computer what to do in order to produce a certain desired outcome. Every time you do search on internet through any search engine like Google or look at your Facebook feeds or use GPS navigation in your car, you are directly or indirectly interacting with an algorithm. Individuals often demonstrate greater trust on assistance from algorithms compared to non-algorithmic assistance, displaying algorithmic obligation. Counting on algorithms for analytical tasks is typically beneficial. Even simple algorithms, such as weighting all variables equally, can outclass humanoid prediction. Algorithms have begun to intrude on tasks conventionally earmarked for human judgment and are progressively proficient of performing well in innovative and tough tasks. Moreover, at the same time, societal impact, through social media, personal networks, or online assessments and reviews, is one of the most compelling forces affecting individual decision-making.

In short, algorithms are the core entity of the internet, and they manage and run the internet and all online activities like financial transactions, crypto/stock trading, searching, customized browsing, data manipulation, etc. Email knows the destination address and thus knows where to go thanks to the underlying algorithms. Moreover, smartphone mobile apps are nothing but algorithms. Computer and video games are algorithmic storytelling. Book or movie recommendation, online dating, leisure\travel web portals, and so on would not function properly and efficiently without algorithms. Artificial intelligence (AI) is nothing but algorithms. GPS mapping systems make use of algorithms to get entity from location X to location Y. Every single piece of the object people see on social media is brought to them by means of algorithms. Moreover, everything people do in everyday life and see on the web is an outcome of some algorithm or other. Every time we sort or arrange data in a worksheet, algorithms plays vital role, and almost every financial transaction is accomplished today by algorithms. Algorithms make every electronic gadget to respond to voice commands, organize and sort photos, recognize and identify faces, and build and drive automobile cars. Hacking, cyberattacks, and cryptographic code-breaking exploit algorithms to the next level. Algorithms are often sophisticated, elegant, and amazingly useful tools used to accomplish various categories of tasks. They are mostly hidden and invisible aids, enhancing and augmenting human lives in increasingly efficient ways. Algorithms will continue to face

#### *Introductory Chapter: Search Algorithm: Essence of Optimization DOI: http://dx.doi.org/10.5772/intechopen.104844*

the ever-increasing impact over the next few decades, influencing people's work and personal lives and the ways they interact with information, organizations like health care service providers, not-for-profit/government institutions, banking/financial sector, retailers/traders, education, media corporates houses and entertainment industry, and each other. The hope is that algorithms will help people swiftly and impartially perform the tasks and get the desired products, information, and services. The major apprehension is that algorithms can deliberately or unconsciously create discrimination and thus enable social engineering to create biased narrative and have other harmful societal impacts.

The term algorithm which finds application in computer science is universally used to describe problem-solving methods that help for the implementation of computer programs. Mostly, algorithms involve complicated methods of manipulating and organizing the data involved in the computation. Basically, they involved the manipulation of data based on some mathematical model and which typically find applications of: searching, sorting, string processing, geometric algorithms, graph algorithms, genetic algorithms (GAs), neural network, etc.
