Let me start this section by giving the Wikipedia definition for Big Data:
Big data is a term for data sets that are so large or complex that traditional data processing applications are inadequate to deal with them. The term "big data" often refers simply to the use of predictive analytics, user behaviour analytics, or certain other advanced data analytics methods that extract value from data, and seldom to a particular size of data set.
- Wikipedia
Let's try explaining, the two sentences that are given in the preceding Wikipedia definition. Earlier, big data referred to any data that is large and complex in nature. There isn't any specified size of data for it to be called big data. This data was considered so big that conventional data processing applications found it difficult to use it in a meaningful fashion. In the last decade or so, many technologies have evolved in this space in order to analyze such big data in the enterprise. Nowadays, the term big data is used to refer to any sort of analysis method that can comprehend and extract this complex data and make valuable use of it in the enterprise.
Whenever you encountered the term big data being overly used, you must have come across an important aspect with regard to it, called 4Vs (until recently, it was 3Vs, and then the fourth, very significant, V got introduced). The 4Vs, namely variety, velocity, volume, and veracity (in no particular order) determine whether the data we call Big Data really qualifies to be called big:
- Variety: In the context of big data, variety has a very important place. Variety refers to vivid types of data and the myriad sources from which these are arrived at. With the proliferation of technologies and the ever-growing number of applications (enterprise and different personal ones), there is high emphasis on data variety. This is not going to come down any time soon; rather, this is set to increase over a period of time, for sure. Broadly, data types can be categorized into structured and unstructured. Applications during this time deal mainly with structured data stored mostly in a relational database management system (RDBMS). This is very common, but nowadays, there has been the need to look at more unstructured data, and some of the examples can be video content, image content, file content in the form of binaries, and so on.
- Velocity: In the context of big data, velocity is referred to in two aspects. First is the rate at which the data is generated, and second is the capability by which the enormous amount of data can be analyzed in real time to derive some meaningful conclusions. As the proverb goes, Time is money, this V is a very important aspect, which makes it easy to take quick decisions in real time. This aspect is one of the strongholds of some of the businesses, especially retail. Giving the customer a personalized and timely offer can be the deciding factor of the customer buying a product from you or ditching you to select a more favorable one.
- Volume: In the context of big data, volume refers to the amount/scale of data that needs to be analyzed for a meaningful result to be derived. There isn't a quantitative figure that categorizes a data to be falling into big data. But usually, this volume is definitely more than what a conventional application is handling as of now. So, in general, this is quite big and does pose a problem for a traditional application to deal with in a day-to-day fashion (OLTP - OnLine Transaction Processing). For many businesses, analyzing and making use of social data has become a necessity. These social apps (Facebook, Google+, LinkedIn, and so on) have billions of registered users producing billions of data (structured and unstructured) in a day-to-day fashion. In addition to this, there are applications that themselves produce a huge amount of data in the form of conventional transactions and other analytics (behavioral, location-based, and so on). Also, with the growing number of wearables and sensors that emit data every millisecond, the volume aspect is going to be very important, and this is not going to come down any time soon.
As detailed in the previous section, until recently, there used to be 3Vs. But quite recently, the fourth V was introduced by IBM, namely veracity. For data growing at an exponential rate and as deduced from different reliable and unreliable sources, the significance of this V is huge.
You must have already heard/read of fake news/material being circulated in various social media when there is something important happening in the world. This V brings this a very important aspect of accuracy in big data. With proliferation of data, especially in social channels, this V is going to be very important, and rather than 3Vs, it is leaning highly towards 4Vs of Big Data.
- Veracity: In the context of big data, veracity refers to accuracy of data being analyzed to get to a meaningful result. With a variety of sources, especially the not-so-reliable user-entered unstructured data, the data coming from some of these channels has to be consumed in a judicial manner. If an enterprise wants to use this data to generate business, its authenticity has to be verified to an even greater extent.
Big Data and its significant 4V's are shown in a pictorial representation, as follows:
Figure 03: 4V's of Big Data
Figure 03 clearly shows what the 4V's are and what each of these V's means, with adequate bullet points for easy understanding.