What Is Ethereum? A Beginner's Guide to Smart Contracts and Gas Fees (2026)

Ethereum is a decentralized blockchain network and software development platform built on the cryptocurrency Ether (ETH). While Bitcoin is specialized as "digital gold" for storing value and transferring funds, Ethereum is designed as a programmable blockchain that serves as the foundation for thousands of applications, including DeFi (decentralized finance), NFTs, gaming, decentralized social media, and stablecoins. This article explains the core concepts of smart contracts and gas fees on Ethereum, highlighting key design differences compared to Bitcoin.

What Are Smart Contracts?

A smart contract is a program that automatically executes when predefined conditions are met. Stored as code on the Ethereum blockchain, once deployed (published), it carries out operations according to those conditions without any third-party intervention.

Think of a vending machine: you insert coins and select a product, and the machine automatically dispenses the item. Similarly, a smart contract executes a predetermined action (e.g., transferring a digital asset) once specific conditions are satisfied (e.g., receiving a certain amount of ETH). This mechanism enables trusted, automated transactions without the need for intermediaries.

By incorporating smart contract functionality, Ethereum has evolved beyond a simple payment network into a platform for "programmable money." Developers can build their own applications on top of Ethereum, a capability that underpins the diversity of today's cryptocurrency ecosystem.

What Are Gas Fees?

Gas fees are the transaction fees paid to execute transactions or run smart contracts on the Ethereum blockchain. These fees are paid in ETH as compensation for utilizing the network's computational resources.

The amount of the gas fee fluctuates based on the complexity of the transaction and the level of network congestion. Executing complex smart contracts requires more computational resources than a simple ETH transfer, resulting in higher gas fees. Additionally, during periods of high network congestion, users must pay higher gas fees to have their transactions processed with priority.

Gas fees also play a crucial role in preventing network abuse. By imposing a cost on every operation, it becomes economically prohibitive to repeatedly execute meaningless transactions or programs, thereby maintaining network stability. Please note that specific gas fee amounts and calculation methods are subject to change; therefore, we recommend checking the official Ethereum documentation for the latest information.

Design Differences Compared to Bitcoin

While both Bitcoin and Ethereum are built on blockchain technology, there are clear differences in their design philosophies and objectives.

Bitcoin was primarily designed for "store of value" and "peer-to-peer transactions." Its scripting language is intentionally kept simple, preventing the execution of complex programs. In contrast, Ethereum was designed as a "platform for decentralized applications" and employs a Turing-complete programming language. This theoretically allows any kind of program to be executed on the blockchain.

There are also differences in token issuance and economic models. Bitcoin has a fixed supply cap of 21 million coins, whereas Ethereum does not have a fixed issuance limit. However, Ethereum has implemented a mechanism that burns (destroys) a portion of transaction fees, thereby adjusting the supply. These design differences influence the use cases and characteristics of each blockchain.

Ethereum Trends in 2026

Ethereum's technology continues to evolve. In 2026, the next major upgrade, "Hego," is scheduled, with features under consideration to enhance resistance to transaction censorship and enable more flexible application development. Specifically, two Ethereum Improvement Proposals (EIPs)—FOCIL and Frame Transactions—are receiving significant attention.

Additionally, initiatives are underway to allow users to pay gas fees without holding ETH. This represents a crucial step toward lowering the barrier to entry for using Ethereum, making its applications accessible to a broader audience. While these technical advancements are expected to improve Ethereum's usability and functionality, their actual impact and adoption rates will depend on future development progress and market dynamics.

Key Considerations When Getting Started with Ethereum

Before investing in or using Ethereum, it is essential to understand the associated risks. As with cryptocurrencies in general, prices are highly volatile, and there is a possibility of losing your principal investment. Additionally, smart contracts may contain bugs or vulnerabilities, meaning the risk of hacking is never zero.

Furthermore, regulations and tax treatment regarding Ethereum transactions vary by country and region. In Japan, cryptocurrency trading is regulated by law, and specific tax rules apply. Before you begin trading, we recommend fully understanding these regulations and seeking professional advice if necessary.

If you are considering participating in the Ethereum ecosystem, it is crucial to choose a reliable exchange by referring to our cryptocurrency exchange comparison. Since fees, supported currencies, and security measures differ among exchanges, be sure to select one that best suits your needs.

Summary

Ethereum is a blockchain platform capable of executing smart contracts, built on design principles distinct from Bitcoin. Gas fees are the transaction costs required to utilize the network, fluctuating based on transaction complexity and network congestion. As of , technical upgrades continue to be implemented, making it a sector with significant potential for future growth.

However, investing in cryptocurrencies carries high risks. It is crucial to fully understand risks such as price volatility, hacking, and regulatory changes, and to make decisions at your own responsibility. We hope this article has helped deepen your foundational knowledge of Ethereum.

Risks and Disclosures

Risk: Cryptocurrencies are highly volatile and involve the risk of loss of principal. This article provides general information based on data as of 2026-09-09; it does not constitute investment solicitation, advice, or a recommendation for any specific asset. Trading eligibility and tax regulations vary by country/region, so please verify local regulations and the latest terms of each exchange before trading.

Affiliate Disclosure: This article may contain advertising (affiliate) links, through which our site may earn compensation at no additional cost to you. Such compensation does not influence our editorial ratings or content.

Frequently Asked Questions

What is the difference between Ethereum and Bitcoin?

Bitcoin is a simple blockchain primarily designed for storing value and transferring funds, while Ethereum is a programmable platform that can execute smart contracts. On Ethereum, a wide range of applications such as DeFi and NFTs are built.

What are gas fees?

Gas fees are charges paid in ETH to execute transactions or smart contracts on the Ethereum blockchain. The amount varies based on transaction complexity and network congestion.

What risks are associated with Ethereum smart contracts?

Smart contracts can contain code bugs or vulnerabilities, which pose hacking risks. Also, once deployed, they can be difficult to modify, so it's important to choose audited projects and exercise caution when using them.

What does the future hold for Ethereum gas fees?

As of 2026, efforts are underway to allow users to pay gas fees without holding ETH and to improve network efficiency through upgrades. Specific fees and mechanisms may change with future development, so checking official sources is recommended.