What is Solana?

What kind of blockchain is Solana?

Solana is a layer 1: an independent blockchain with its own validators, its own consensus and its own coin, SOL. It does not settle to another chain. Like Ethereum, it runs smart contracts, so people use it for tokens, trading apps and payments. Unlike Ethereum, whose scaling plan centres on layer 2 networks, Solana is designed to handle activity on the base chain itself.

Security comes from proof of stake. Validators lock up SOL, and Solana's documentation defines stake as tokens forfeited to the network if malicious validator behaviour can be proven. A rotating leader schedule decides which validator produces the block in each time slot.

What is proof of history, and why does Solana need it?

Computers spread around the world disagree slightly about the time. Most blockchains spend messages and waiting time settling on an order of events. Solana's whitepaper, written by Anatoly Yakovenko, proposes a shortcut it calls proof of history.

The idea is a running chain of hashes. A validator repeatedly hashes the previous output, so each result can only be produced after the one before it. When a transaction is mixed into that chain, the next hash proves the transaction existed before that point. Anyone can later re-run the sequence and confirm both the order and that time passed between entries.

Proof of history is not a consensus mechanism on its own. The whitepaper pairs it with proof of stake: the leader produces the sequence, and other validators vote to confirm it. A shared clock means validators spend less effort agreeing on order, which is part of how Solana keeps its slots short — roughly 400 milliseconds each, according to its documentation.

How does Solana run transactions in parallel?

On many blockchains, transactions are executed one after another. Solana's runtime, which its documentation calls Sealevel, can run them side by side. This works because every Solana transaction must declare up front every account it will touch and whether it will only read it or also write to it.

If two transactions write to different accounts — say, two strangers each paying someone else — they cannot interfere, so the validator can process both at once. If they write to the same account, they are queued. Programs themselves are stateless: the code lives in one account and the data it changes lives in separate data accounts passed in with each instruction.

A transaction bundles one or more instructions. Solana's docs say they are atomic: either all instructions succeed or all are reversed — and the fee is still charged if the transaction fails. A transaction must also reference a recent block hash, which stays valid for 150 slots, about a minute.

How much does a Solana transaction cost?

Fees are counted in lamports, Solana's smallest unit: one lamport is 0.000000001 SOL. Every transaction pays a base fee of 5,000 lamports per signature. Half of that base fee is burned and half goes to the validator that processed it. Users can add an optional prioritization fee to move ahead in busy periods; it is calculated from a price per compute unit (measured in micro-lamports) times the compute units the transaction requests, and goes entirely to the validator.

How does Solana compare with Ethereum?

Because its programs do not run on the Ethereum Virtual Machine, Solana is not EVM-compatible: Ethereum contracts and wallets do not carry over directly.

What does Solana trade away for speed?

Speed has a price in hardware. Agave, a Solana validator client maintained by Anza, lists 12 cores or more, 256 GB of RAM or more, multiple fast NVMe drives and at least a 2 Gbit/s connection for a staked validator. Ethereum's documentation puts a full node's minimum at 16 GB of RAM. Fewer people can afford Solana-class machines, which is the heart of the blockchain trilemma.

The Bank for International Settlements made this point in 2022, arguing that newer layer 1s such as Solana gain capacity at the cost of greater centralisation and weaker security. That is the BIS's assessment; others weigh the trade-off differently, so treat it as a design choice to understand rather than a settled verdict.

What mistakes do beginners make with Solana?

• Quoting the whitepaper's 710,000 transactions per second as real. The whitepaper presents it as a theoretical ceiling on a 1 gigabit network, not measured performance.
• Assuming a failed transaction is free. Solana charges the fee even when a transaction reverts.
• Ignoring upgrade keys. A program deployed with the upgradeable loader can be changed by whoever holds its upgrade authority; it becomes immutable only when that authority is revoked.
• Mixing up networks. A Solana address is not an Ethereum address. Sending tokens to the wrong chain format can mean losing them — check the address and network first.