What is Polkadot, anyway?

But this course isn't just for developers. you maybe a tech enthusiast, or maybe a non-technical stakeholder in the Polkadot or the overall web3 ecosystem overall. If you want to understand Polkadot at a high level—without writing much code—there's plenty here for you too. We'll explain concepts simply, with real-world analogies, so you can appreciate the power of Polkadot even if you don't plan to touch Rust or Substrate.

The goal is to lower the barrier of entry for everyone, making Polkadot accessible, practical, and exciting.

Jumping into Polkadot development shouldn't feel like climbing a mountain on Day 1. This course is built to ease you in gradually:

1. We Start Simple: You'll learn what Polkadot is, how it works, and why it's special.

2. Move on your own pace: There's no immediacy of in-person learning. It's designed to be tuned to your own pace, and keep as a reference for whenever you want to come back to.

3. We Build Together: Throughout the course, you'll work on a real-world project called CertiDOT—a decentralized credential verification system. It's a project that will teach you key skills like smart contracts, node setups, and eventually, blockchain customization.

4. We Level Up Step-by-Step:

- First, you'll get familiar with the basics: blockchain layers, the Polkadot ecosystem, and developer tools.

- Next, you'll write smart contracts using Ink!, Polkadot's smart contract language.

- Finally, we'll explore Substrate—the framework for building custom blockchains—and take CertiDOT live.

By the end, you won't just understand Polkadot—you'll have something real to show for it.

Good news: the prerequisites for this course are light.

- Rust: If you've never worked with Rust before, don't panic. Rust is powerful, but it can feel a bit intimidating for beginners. Fortunately, tools like AI-assisted editors (such as GitHub Copilot or Cursor) will make writing Rust code far less daunting. We'll also provide plenty of examples to guide you.

- Minimal Setup: A computer, a code editor (like VS Code), and an internet connection are all you need. No fancy machines or deep technical setup.

If you've got curiosity and a willingness to learn, you're ready.

To understand what makes Polkadot so powerful, let's start with the basics: blockchain layers.

Think of blockchain technology like building a city:

- Layer 1 is the city itself—blockchains like Ethereum or Solana. All the action happens here: transactions, smart contracts, decentralized apps (dApps). But there's a problem: as more people move in, the city gets crowded, and traffic (gas fees) skyrockets.

- Layer 2 is like adding express lanes or public transportation—solutions built on top of Layer 1 to help with congestion. Think Base, the Layer 2 solution built on top of Ethereum.

Abstracting all these, Layer 0 is the foundation—the infrastructure that makes it possible to build cities and connect them. This is where Polkadot comes in. Polkadot is the infrastructure to build interconnected Blockchains, build apps on top of them, and much more.

Polkadot is the Layer 0 that ties everything together—a network of blockchains that can scale, collaborate, and innovate. To view it from top, Polkadot is a thriving ecosystem of connected Blockchains with a variety of use cases and dApps built on top of them.

It's a platform where different blockchains (called parachains) can:

- Work together: Blockchains can send data, messages, or assets to each other seamlessly.

- Scale efficiently: Polkadot splits the load across parachains instead of clogging a single chain (like Ethereum).

- Share security: All parachains rely on the same security provided by Polkadot's Relay Chain—the heart of the network.

Here's how Polkadot works:

- The Relay Chain: This is the main chain of Polkadot. It handles security, consensus, and communication. Think of it as the backbone that supports everything else.

- Parachains: These are independent blockchains that connect to the Relay Chain. Each parachain can have its own rules, use cases, and governance. They're customizable, scalable, and efficient.

Shared Security: Instead of every parachain worrying about its own security, they all inherit the security of the Relay Chain. It's like sharing the same team of bodyguards—it saves time, money, and effort.

This modular design makes Polkadot incredibly powerful and developer-friendly.

Comparing Blockchain ecosystems is always a nuisance affair. Certain ecosystems are powerful for specific things, and it is often easy to oversimplify the impact of a particular ecosystem when comparing with others. Nonetheless, let's talk about a balanced comparison among Polkadot and some other similar ecosystems, such as Ethereum (most popular), Solana (rising star in popularity), and Cosmos (a similar interconnected Blockchain approach).

Ethereum is the foundation of most blockchain innovation today. It introduced the world to smart contracts and decentralized applications (dApps) and still dominates in every metric in adoption. Gavin Wood, the founder of Polkadot, is also the co-founder of Ethereum.

Ethereum is not strictly comparable with Polkadot, as Ethereum is a layer 1 Blockchain with strict execution model and is suitable for building dApps. Polkadot is built on the premise of a multichain world, and thrives to be the infrastructure for enabling that.

Solana is celebrated for its high throughput—processing tens of thousands of transactions per second—and is often the go-to for developers seeking speed. But this speed comes at a cost. Solana relies on high-performance hardware for its validators, which raises the barrier to entry and compromises decentralization. Additionally, network reliability has been a concern, with Solana experiencing multiple outages in recent years.

Polkadot, while not as fast in raw transaction speeds, achieves scalability through its parachain structure. Each parachain can scale horizontally, and the network as a whole maintains a decentralized architecture with robust security mechanisms. The trade-off? Stability, security, and scalability without centralization compromises.

Cosmos shares Polkadot's vision of blockchain interoperability but approaches it differently. Its Inter-Blockchain Communication (IBC) protocol allows independently secured blockchains to exchange data. However, this independence creates a challenge: each chain must establish its own security, increasing the development burden and the risk of vulnerabilities.

Polkadot's approach simplifies this with shared security. Parachains connected to Polkadot inherit the security of the Relay Chain, which is maintained by a decentralized pool of validators. This means developers can focus on building functionality rather than worrying about securing their chain—a huge advantage in terms of time and resources.

Polkadot bridges the best features of these blockchains. It scales like Solana, connects blockchains like Cosmos, and offers developer tools comparable to Ethereum. But it doesn't stop there. Its shared security, on-chain governance, and ability to adapt to new innovations make it a future-proof platform. For developers looking for a blockchain built to collaborate rather than compete, Polkadot is a natural choice.

Polkadot is a blockchain that evolves without disruption. Unlike traditional blockchains, which often require hard forks—splitting the network into two versions—to implement upgrades, Polkadot's design embraces seamless evolution. Through its on-chain governance, the Polkadot Relay Chain can be upgraded automatically using a decentralized voting process. This means developers and stakeholders propose and approve updates, which are enacted without downtime or contentious splits in the community. This capability not only ensures Polkadot remains future-proof but also cements its place as a dynamic and adaptive blockchain ecosystem.

What truly sets Polkadot apart is its governance structure. Polkadot operates as the largest decentralized autonomous organization (DAO) in the world, where decisions about the network's evolution are made collectively by token holders and on-chain mechanisms. The OpenGov system facilitates continuous proposals and voting, ensuring community alignment while keeping the system agile. This DAO-first approach reflects the core ethos of Web3: decentralization, collaboration, and community-driven innovation. It's not just a blockchain—it's a blockchain that listens, evolves, and adapts with its community at the helm.

The Polkadot ecosystem is built with developers in mind. With over 2,400 active monthly developers it's one of the fastest-growing blockchain ecosystems. This developer base has grown steadily, fueled by Polkadot's robust tools, funding opportunities, and supportive community.

Polkadot's development framework, Substrate, is a game-changer. Substrate abstracts away many of the complexities of building a blockchain. Need consensus? Networking? Runtime logic? Substrate handles these for you, allowing developers to focus on creating their application logic. Projects built with Substrate can connect seamlessly to Polkadot's Relay Chain as parachains or run independently.

Substrate is one of the reasons Polkadot's developer onboarding is smoother than platforms like Ethereum, where developers often struggle with the complexity of Layer 1 dApp development.

Polkadot also supports smart contract development through Ink!, a Rust-based language. Ink! compiles to WebAssembly (Wasm), which is fast, portable, and future-proof. Developers familiar with Rust (already a popular systems programming language) find Ink! relatively easy to pick up. Wasm ensures that smart contracts built today can operate across blockchains tomorrow.

These technical tools make Polkadot attractive, but what really sets it apart is the ecosystem of funding and resources designed to support developers.

Polkadot's commitment to innovation is evident in its financial support for developers. The Web3 Foundation Grants Program has already funded over 600 projects across the Polkadot and Kusama ecosystems. These grants target everything from dApps to infrastructure.

In addition to grants, Polkadot's on-chain treasury provides funding through the OpenGov model. Community members propose initiatives, and the treasury allocates funds based on governance decisions. In the first half of 2024, the treasury distributed over 11 million DOT (Polkadot's native token) or 87m USD to support infrastructure, community events, and education initiatives. This model ensures that the ecosystem grows democratically, with funds going to projects that align with community priorities.

While Ethereum remains the leader in terms of developer numbers and activity, Polkadot is rapidly closing the gap with its unique focus on interoperability, scalability, and ease of use. Solana and Cosmos, while innovative, face challenges in reliability and fragmentation that Polkadot's shared security and unified infrastructure address directly.

Polkadot's ecosystem is still young compared to Ethereum, but its growth trajectory suggests it's building a foundation for long-term innovation. Developers are drawn not just by the tools and funding but by the vision of a connected, decentralized future that Polkadot enables.

Polkadot is more than a blockchain—it's a developer's ecosystem. It offers a scalable, interoperable, and secure platform while backing innovation with grants, a treasury, and tools like Substrate and Ink!. For developers, Polkadot is a playground of possibilities, ready to turn ideas into impactful projects.

Polkadot isn't just another blockchain—it's a platform for innovation. Whether you're a developer looking to build or an enthusiast curious about the future of Web3, Polkadot's architecture opens up new possibilities.

In the next lesson, we'll introduce your first project: CertiDOT. You'll learn what it's about, how it works, and set up your development environment to start building.

Polkadot's superhighway awaits. Ready to get on board?