Emerging Trends: Cloud Computing, Grid Computing and Blockchain

Hello students, welcome to Kwickprep. Your photos are safe even if your phone is lost. Where are they actually kept? Today we will learn cloud computing and its three service models, grid computing, and blockchain as a shared ledger. We will finish with their uses and risks.

Cloud computing means using computing services over the internet, instead of on your own computer. The cloud is not in the sky. It is huge data centres full of servers, owned by companies. They offer storage, servers, software and databases. You pay only for what you use, or use a free plan with limits. And you can reach your data from anywhere, on any device with internet.

You already use the cloud every day. Google Drive and OneDrive store your files on their servers. Gmail keeps your emails on servers, not only on your phone. DigiLocker, run by the Government of India, keeps digital copies of documents like mark sheets. Online office apps like Google Docs let you edit a file in the browser.

Cloud services come in three main service models. IaaS means Infrastructure as a Service, where you rent virtual servers, storage and networks, like Amazon Web Services or Microsoft Azure. PaaS means Platform as a Service, where you get a ready platform to build and run your own apps, like Google App Engine. SaaS means Software as a Service, where you simply use ready software in a browser or app, like Gmail or Zoom.

Here is an easy way to remember them. IaaS is like renting a kitchen, so you still cook everything yourself. PaaS is like buying a ready pizza base, so you only add toppings, which is your own app. SaaS is like ordering a pizza delivery, so you just eat, and the company manages everything.

Pause and predict. A school uses Google Classroom to give homework. Is that IaaS, PaaS or SaaS? The answer is SaaS. The school does not build or manage anything, it simply uses ready software.

Now grid computing. In grid computing, many separate computers, often in different places, join together to act like one super computer. A very big task is split into small parts. Each computer in the grid works on its own part, often using its spare time. Finally, all the results are combined into one answer.

Let us follow a task through a grid. A big task arrives, like analysing weather data for a whole country. Middleware, the managing software, splits it into small parts. It sends the parts to many computers across the grid. Each computer works on its part at the same time. The results come back and are combined into the final answer.

Students often mix up cloud and grid, so compare them. Cloud computing is about renting ready services from a provider. Its resources are owned and managed by one provider, while a grid joins computers owned by many groups, like universities. Cloud suits everyday apps and websites, while a grid suits huge science jobs, like studying particle physics data.

Now blockchain. First, a ledger is a record book of transactions, like a shopkeeper's khata book. In a blockchain, the ledger is shared, so every member of the network keeps the same copy. New records are grouped together and added as a block. Once a block is added, it cannot be changed secretly, because everyone else's copy would not match.

Watch how blocks join into a chain. A hash is a short code calculated from a block's data, like a fingerprint. Block two stores the hash of block one, called hash A. Block two then gets its own hash, hash B. Block three stores hash B, so every block points back to the one before. Now suppose someone edits block two. Its hash changes, it no longer matches block three, and every member can see the tampering.

Let us see where each technology is used. Cloud computing powers online storage, business apps, online classes and email. Grid computing helps with weather forecasting and medical research, like testing new medicines. Blockchain is behind cryptocurrencies like Bitcoin, and is being tested for keeping land records safe from tampering.

Every technology also has risks. Cloud services need good internet, and your data sits on someone else's servers, so privacy and hacking are concerns. A grid is hard to manage, because the computers belong to different owners. Some blockchains use a lot of electricity, and because records cannot be changed, a wrong entry is hard to undo.

A few habits keep your cloud data safe. Use a strong password that you do not use anywhere else. Turn on two step verification, so a code on your phone is also needed. And check who you share a file or folder with before you click share.

Let us revise. Cloud computing gives computing services over the internet. IaaS rents servers, PaaS gives a platform to build apps, and SaaS gives ready software. Grid computing joins many computers to share one big task. A blockchain is a shared ledger of blocks linked by hashes. And always weigh the risks, like internet dependence, privacy and energy use.