Web3 and DeFi: How Blockchain Is Reshaping the Internet and Finance

Web3 and DeFi have become two of the most closely watched directions in tech. One attempts to restructure the underlying power dynamics of the internet, while the other targets the pain points of the traditional financial system. This article is based on the core arguments of a Spanish-language tech commentary, combined with industry context for further analysis, to help readers understand what problems these two technologies are actually solving.

Web3: Returning Control of Data and Transactions to Users

According to the original article, Web3 is the next-generation internet built on blockchain technology, with a core promise of providing greater security and privacy protection. The current Web2 era is dominated by centralized platforms, where users' transaction records and personal information are effectively controlled by large corporations and financial institutions. Web3 seeks to change this landscape through a decentralized architecture.

Specifically, Web3 applications allow users to control their own information and ensure that online transactions are completed in a secure, decentralized manner. The original article mentions that this model has given rise to decentralized applications (DApps) and blockchain-based incentive systems, providing a new economic model for users to participate in network building.

From a technical logic perspective, Web3's value proposition is not just "more secure" — it shifts trust from institutions to the protocol itself. Users no longer need to trust that a platform won't misuse their data; instead, they rely on publicly verifiable code rules. The significance of this shift lies in how it redefines the power relationship between users and platforms.

Blockchain is the shared technological foundation of both Web3 and DeFi, and understanding it helps clarify how both technologies operate. A blockchain is essentially a distributed ledger where data is packaged into "blocks" and chained together in chronological order, with each block containing the hash of the previous block, forming a chain that is extremely difficult to tamper with. The ledger is maintained collectively by numerous nodes across the network, and no single node can modify records on its own. This structure brings two key characteristics: first, decentralization — it does not rely on a central authority for endorsement; second, verifiability — anyone can independently verify transaction history. It is precisely these characteristics that enable Web3 to shift trust from platforms to public code, and allow DeFi to complete lending and trading without intermediaries like banks. However, decentralization also comes with trade-offs in performance and cost — for example, transaction confirmation speed and fees fluctuate with network congestion.

DeFi: An Alternative Beyond the Traditional Financial System

The original article's assessment of the current fintech landscape is quite direct: despite years of fintech development, control over information and transactions remains concentrated in the hands of large corporations and financial institutions. DeFi (Decentralized Finance) is the alternative proposed in response to this status quo.

DeFi is built on the same blockchain foundation as Web3, with the goal of providing a financial service model that is more secure and efficient than traditional financial institutions. The original article points out that DeFi gives users the opportunity to create their own decentralized financial applications, thereby participating in the value distribution of the digital economy, rather than merely passively accepting products offered by institutions.

The appeal of this approach lies in being "permissionless" — anyone with an internet connection can access lending, trading, wealth management, and other financial services without going through traditional financial institutions' review processes. But this also means users need to bear more responsibility themselves, including private key management and smart contract risks.

Smart contracts are the core component of DeFi's operation, and can be understood as programs deployed on the blockchain that execute automatically. When preset conditions are met, the contract automatically completes operations such as transfers, liquidations, or collateralization according to code rules, without human intervention or third-party guarantees. For example, lending protocols manage deposits, lending, and interest calculations through smart contracts, with the flow of user assets controlled by public code. This "code is law" mechanism reduces intermediary costs and increases the transparency and auditability of operations. But smart contracts are not without risks: once a vulnerability exists in the code, attackers may exploit it to transfer funds, and on-chain transactions are typically irreversible, making losses difficult to recover. Therefore, whether a DeFi project has undergone sufficient auditing and whether contracts are upgradeable become important references for users assessing risk.

The Intersection of the Two Technologies and Their Shared Narrative

Although Web3 and DeFi have different emphases, they share the same technological foundation — blockchain. The original article emphasizes that the combination of the two allows users to gain security, privacy, and independence in both their financial experience and digital lives.

This "combined narrative" is not uncommon in industry discussions. Web3 provides decentralized infrastructure at the identity and data layers, while DeFi builds financial applications on top of it. The two support each other: without Web3's decentralized identity and data layers, DeFi's "trustless" promise would be difficult to fully deliver; without DeFi's economic incentives, participants in the Web3 ecosystem might also lack sustained motivation.

The original article calls on readers to pay attention to this trend by "staying ahead," but from the perspective of actual development, Web3 and DeFi are still in their early stages, with infrastructure performance, regulatory frameworks, and user experience all having numerous issues yet to be resolved.

DApp (Decentralized Application) is a typical vehicle at the intersection of Web3 and DeFi. Unlike traditional mobile apps, a DApp's backend logic runs on a blockchain or decentralized network, with the frontend typically serving only as an access point. Users interact with DApps through crypto wallets, where the wallet address serves as the identity marker, requiring no account registration or submission of personal information. This design returns identity and data control to users, but also introduces new barriers: users must manage their own private keys, and once lost, assets cannot be recovered, nor is there customer service to assist with restoration. Additionally, DApp operation often requires paying network fees (such as gas fees), with costs depending on on-chain congestion. These characteristics determine that DApps are currently better suited for users with some technical understanding, and there is still a distance to go before mass adoption by ordinary consumers.

Several Practical Issues That Require Sober Consideration

While the original article maintains an overall positive attitude when introducing Web3 and DeFi, it also indirectly reveals some tensions worth noting. For instance, the original article acknowledges that the current Web is still dominated by centralized models, and Web3 alternatives have yet to become mainstream. Although DeFi claims to be more secure, incidents of smart contract vulnerabilities and protocol attacks are not uncommon in the industry.

Another easily overlooked issue is user experience. The operational barrier for decentralized applications remains significantly higher than traditional internet products, and issues such as private key loss and gas fee fluctuations are not user-friendly for ordinary users. This is also one of the main obstacles for Web3 and DeFi moving from the geek community to the mass market.

The ending of the original article was truncated, failing to fully present the definition of DeFi and subsequent discussion. Therefore, this article's analysis of DeFi is mainly based on the content presented in the original text and general industry knowledge, and readers are advised to cross-verify with more sources.

Conclusion

Web3 and DeFi represent a reimagining of the power structures of the internet and financial systems. Their core proposition — users controlling their own data and assets — has clear appeal, but from technological maturity to actual adoption rates, there is still a considerable distance to truly delivering on these promises. For readers following this field, continuously tracking technological progress and risk events is more valuable than chasing the concepts themselves.