"What distinguishes Bitcoin (BTC), Ethereum (ETH), and blockchain technology from one another?"

Bitcoin (BTC) was the first cryptocurrency to be invented, launching the blockchain technology concept into mainstream discussion.

While BTC and Ethereum (ETH) both use blockchain technology, Bitcoin's blockchain is dedicated to tracking ownership of the cryptocurrency, whereas Ethereum's supports complex programmable transactions.

Ethereum's primary function is to act as a platform for the execution of smart contracts, which are self-executing agreements with the terms directly written into code.

BTC has a maximum supply of 21 million coins, ensuring scarcity, while ETH does not have a hard cap, allowing for continuous issuance.

Bitcoin's transaction speed is typically slower than Ethereum's due to its scalability limitations.

This is because every transaction needs to be processed by each node in the Bitcoin network.

Ethereum initially used a Proof-of-Work (PoW) consensus mechanism, much like Bitcoin; however, it is transitioning to a Proof-of-Stake (PoS) mechanism called Ethereum 2.0.

PoS relies on users' staked Ether holdings to validate transactions and create new blocks, rather than using energy-intensive mining rigs as in PoW.

In Ethereum's PoS, participants can validate transactions based on the amount of Ether they hold and are willing to 'stake' as collateral, reducing energy consumption.

The programming language, Solidity, was developed for the Ethereum Virtual Machine (EVM) to facilitate the creation and execution of smart contracts.

ERC-20 and ERC-721 are token standards on the Ethereum network that allow for the creation and implementation of fungible and non-fungible tokens (NFTs), respectively.

Decentralized Applications (dApps) are applications built on Ethereum that execute on the blockchain, offering increased security and reduced downtime compared to traditional server-based applications.

Due to its smart contract flexibility, Ethereum is considered Turing-complete, which means it can solve any problem given enough time and resources, unlike Bitcoin's scripting language.

The Ethereum network has experienced notable scaling issues, such as high gas fees, due to its popularity, leading to the development of layer-2 solutions such as Optimism, Arbitrum, and Polygon to alleviate such problems.

In comparison, Bitcoin's Lightning Network is a layer-2 solution designed to facilitate faster and cheaper transactions by creating off-chain payment channels.

Although both BTC and ETH have various use cases, Bitcoin is often considered 'digital gold' and primarily a store of value, whereas Ethereum supports various applications, platforms, and financial services.