Visualise the invisible

The Druvexaa
Knowledge Hub

79 computer science concepts explained in plain English — then shown to you in 3D. Every topic carries its own diagram, the mistake most people make, interview questions, and a simulation you can control.

Five subjects · 79 concepts

Start with Computer Networks See all subjects

About the Knowledge Hub

Made simple, so it actually stays

Most guides do one of two things. They give you a one-line meaning and stop, so you still do not really get it. Or they throw so much detail at you that you give up halfway. Both leave you confused.

The main purpose of the Knowledge Hub is to help you truly understand the concept before you try to visualize it. Some people learn best by reading a clear explanation first, while others learn by seeing it in action. That's why every topic starts with the idea itself, explained in simple language, and then leads you into the interactive 3D simulation. Once you understand the concept, it becomes much easier to visualize the invisible and see what is happening behind the scenes.

Here it works differently. Each topic starts with one easy sentence. Then you see an original diagram. Then we go through it step by step, in plain words—the same way a friend would explain it to you.

After that, you get the part textbooks often skip: the mistake most people make, explained clearly. You'll also find interview questions with simple answers, followed by a link to open the 3D simulation, so you can watch the concept come to life instead of just picturing it in your head.

Nothing here is copied from anywhere. Every diagram was created specifically for Druvexaa, and each topic connects naturally to the next, so you can move from DNS to TCP to routing and beyond without ever getting stuck.

Whether you're learning for the first time, preparing for an interview, or simply curious about how computers work behind the scenes, the goal is the same: to help you understand first, then visualize the invisible with confidence.

How each concept is built

  1. Simple definition

    One or two sentences, no jargon.

  2. Diagram

    Drawn for the concept, not decoration.

  3. Step by step

    The process in order, in plain words.

  4. Real-world example

    Where you have already met it.

  5. The common mistake

    What people get wrong, and why.

  6. Interview questions

    With answers you can actually give.

  7. 3D simulation & quiz

    Watch it, then test yourself.

79

concepts written for Druvexaa

79

diagrams drawn for this hub

295

interview questions answered

35+

3D simulations and quizzes

Start here

Computer Networks

How data actually moves — from a name typed in a browser to a frame on the wire.

Open all 35 concepts →
OSI ModelTCPUDP (and TCP vs UDP)DNSDHCPARPNAT and PATIPv4IPv6RouterDefault GatewaySwitch
HubMAC AddressVLANPAN, LAN, MAN and WANWi-Fi workDifference between Bandwidth and LatencyLoad Balancing and Server SwitchingBus TopologyStar TopologyRing TopologyMesh TopologyWhen you make a mobile call
UPI and card payments workSubnettingPorts and SocketsDifference between HTTP and HTTPSPing and Traceroute workProxies and CDNsEthernetPacket SwitchingUnicast, Broadcast, Multicast and AnycastRouting Protocols (OSPF and BGP)Quality of Service (QoS)

The other four subjects

Everything else in the hub

Operating Systems

How the layer between your programs and the hardware decides who gets what, and when.

RAIDAn OS allocate memoryProcess SchedulingContext SwitchingCritical Section ProblemWhen you power on a computerDeadlockVirtual Memory and PagingMultithreadingDifference between a Semaphore and a MutexAn Operating SystemDifference between Kernel Mode and User ModeSystem CallsFile System
Open Operating Systems →

Cybersecurity

How systems are attacked, and which defences actually hold up in practice.

FirewallVPNAttackers steal passwordsEncryption (AES and RSA)HashingPhishing and Social EngineeringIDS and IPSCIA TriadTypes of MalwareDDoS AttackSQL Injection
Open Cybersecurity →

Artificial Intelligence

What these systems are really doing underneath the demonstrations.

Artificial IntelligenceMachine LearningDeep LearningGenerative AIAgentic AINatural Language ProcessingComputer VisionPrompt EngineeringRetrieval Augmented Generation (RAG)
Open Artificial Intelligence →

Computer Hardware

What the physical parts do, and why the specification sheet keeps misleading people.

The CPU, RAM and OS work togetherWhy does a 32 GB pen drive show only 29.5 GBWhy do USB drives transfer at different speedsAnalog-to-Digital ConversionCache MemoryDifference between an SSD and an HDDCPU Cores, Threads and Clock SpeedGPU and how is it different from a CPUTypes of RAM (DDR, SRAM, DRAM)Motherboard
Open Computer Hardware →

No concept matches that search. Try a shorter word such as dns, raid or ip.

Read it, then watch it move

An explanation gets you halfway. Watching a packet cross a network, a disk rebuild itself, or a process lose the CPU is what makes it stay. Every concept here opens into a simulation you can control.

Browse all 3D simulations Read the Druvexaa Guide