Blockchain is being touted around the world as a disruptive technology that could revolutionize finance, trade, legal systems, digital media, and much more. But blockchain tech has one big obstacle: it’s hard to wrap your head around.

To help laymen better understand blockchain, we reached out to Bitcoin experts around the globe. We issued each of them a challenge: explain blockchain in 150 words or less. As it turns out, even they can struggle to explain blockchain in simple terms.

Blockchain tech is fairly complex, so condensing it down into a one or two paragraphs is no easy task. Comparitech took a stab at the challenge as well, but in video form. Here is our animated explanation of blockchain in less than 150 seconds.

And here are 10 explainers from our gracious experts. We’ve ordered them as best we can from simple and plainly worded to complex and thorough.

Ron Hose, founder of Coins.ph

The Blockchain is a decentralized ledger. In the same way the internet facilitates direct exchange of information (think Skype, WhatsApp vs. traditional telco model), Blockchain facilitates direct exchange of value between parties, without the need for a trusted intermediary.

Drew Ivan, Healthcare Solution Strategist

Blockchain is an immutable, public, distributed ledger that anyone can read or write. Here’s a breakdown of what that means.

IMMUTABLE – data written to a blockchain can never be changed, so readers can be sure it was never altered.

PUBLIC – data on a blockchain is visible to everyone, which makes it perfect for storing public records like bitcoin transactions, land titles, and asset tags.

DISTRIBUTED – unlike a centralized ledger that is kept by a trusted institution, blockchain runs on an entire network of computers, meaning there is no single system that can fail or be compromised.

LEDGER – blockchain is suited to storing small transaction records, not large files.

Taken together, these characteristics allow two parties to trust one another based on the strength of the blockchain network without the need for a third party institution like a bank or government.

Jameson Lopp, Software Engineer at BitGo

A blockchain is a history of events (transactions or otherwise) that uses cryptography to link timestamped batches of events together in order to make it evident if tampering has occurred. This type of data structure enables the creation of new applications that use a blockchain as a trustworthy public database. The first major usage of a blockchain was in Bitcoin as a currency, but many non-payment applications are now being developed on top of Bitcoin and other systems such as Ethereum. Eventually you can expect blockchain-based systems to be used under the hood to power applications that enable users to prove and transfer ownership of digital and physical assets.

Andy Singleton, founder of MAXOS.ai

Bitcoin is a database or “ledger” that shows how much money you have in bitcoins. It simplifies a lot of things because the database is shared. You don’t have to make a special request to your bank to find out how much money you have. It’s all visible in the shared database. You can transfer this money with a digital signature – a sort of instant check. This is a lot faster than a wire transfer where multiple banks have to update multiple databases and then check or “reconcile” them over the course of several days. This type of shared database or “blockchain” will also greatly simplify stock records and trades, tracking and paying for goods, paying musicians for their music, and even medical records. We won’t have to call around to find out where the goods are, when the stock will arrive, or who played what music.

Anatoliy Okhotnikov, financial and cryptocurrencies expert at SoftJourn

Blockchain is an open decentralized database – a distributed ledger. Every participant on the network has a copy of the transaction ledger. Ledger entries are secured by strong cryptography and each transaction must be agreed to by the most of the participants in order to make it into the ledger. This allows for better security, transparency, and trust. Blockchain is a disruptive technology in a sense that it can be used to store any value information like money, goods, property, work, or even votes without the need of a central authority to verify or prove it. The authenticity is verified by the entire community, by everybody who has a copy of the ledger. Cryptography makes sure it is not possible for a single individual or minor group to tamper or forge the ledger records. The future economy is seen to be moving to a distributed and trusted environment and the possibilities with blockchain are endless.

George Harrap, founder of Bitspark.io

Blockchains are a ledger that keeps track of data and the owners of the data. One can use a blockchain to transact data between any connected participant using the blockchain and all participants have the most up to date version of that ledger, ensuring everyone is constantly up to date with the latest. Usually one needs to trust some third party to maintain records of events, but blockchains enable you to transact with people you don’t trust and yet still ensure that their inputs into the blockchain are true. Complex cryptography ensures nobody can falsify a record to try to include data which the other participants haven’t seen or agreed to. Blockchains are open for anyone to track the provenance of the data and simple to audit with no single point of failure by design.

Thomas Glucksmann, Head of Marketing at Gatecoin

Blockchain is an open source value transfer protocol that runs on a distributed peer to peer network and secures transaction records through cryptography. Blockchain was first conceptualized through the release of bitcoin, a decentralized cryptocurrency that stores and verifies transactions on a distributed ledger, known as “the blockchain” designed by a pseudonymous individual or group known as Satoshi Nakamoto.

Since the emergence of bitcoin, many technology and financial institutions have worked to improve upon bitcoin’s blockchain resulting in the development of public and private blockchains, which provide different levels of read and write access to network participants.

Blockchain applications are helping financial institutions to improve the efficiency of many back-office processes through automatic verification, transaction execution and settlement. The technology’s utility extends far beyond finance with use cases for industries as diverse as supply chain to creative rights management that can be disrupted with secure, self-executing trustless value transfers.

Jad Mubaslat, founder and former CEO of BitQuick.co

In 2009, a first-of-its-kind decentralized digital currency program, called “Bitcoin”, was released. Bitcoin utilizes an ongoing immutable cryptographic chain of transactions that acts as a decentralized peer-to-peer ledger. This underlying distributed database has been referred to as “blockchain” technology. All the participants in a blockchain system retain a copy of the ledger, so that if there are any inconsistencies, they will be consolidated against the other copies retained by other participants in the network. In this manner, trust is no longer needed between the entities.

Blockchain can be applied to a variety of use cases where the exchange of value or information is needed between separate entities; this could be the exchange of information in a supply chain, medical information, financial transactions, land ownership and more. Blockchain technology may enable solutions where data can be shared in a distributed manner that increases interoperability, security, immutability and privacy.

Andrew Hinkes, Esq., Partner at Berger Singerman LLP

The Bitcoin Blockchain is a decentralized peer-to-peer network operated over the Internet that relies upon cryptography (called “proof of work”) instead of a trusted third party to confirm transactions of bitcoins between network participants, and that tracks confirmations of those transactions on by circulating constant updates to a chronological ledger of transactions among its participants. A “blockchain” (also called private blockchain, or distributed ledger) is a version of Bitcoin’s blockchain used to control and track transactions of other data. Private blockchains typically rely on a trusted third party or other method of confirmation instead of participant consensus to confirm a transaction. Although both Bitcoin’s Blockchain and private blockchains share may attributes (both are relational databases), the Bitcoin Blockchain’s consensus mechanism makes it economically infeasible to retroactively change the ledger, while private blockchains typically use different confirmation mechanisms that do not offer the same protection.

Marc Kenigsberg, founder of BitcoinChaser

A distributed database composed of a network of interconnected computers that are used to keep a distributed ledger of information. Information exchanges between computers in this kind of database, take on the characteristics of a transaction. These computers use the connection between them to validate these transactions according to a set of parameters, using different kinds of encryption to protect them. As a result, information security on these databases depends on validating data on various computers simultaneously.

This type of decentralized database allows for the programming of smart contracts, essentially complex conditional statement that allow the network to react to predetermined inputs in an autonomous nature without the need for human intervention. The parameters that govern this type of network, will determine the degree to which information is publicly accessible, and the speed at which it travels between computers.