Blockchain technology is new, and a specific vocabulary was created to describe it. Here's a short description of the terms used in this help section that may be new to you.
Recovery Phrase / Mnemonic Seed / Seed Phrase
A list of 12 to 24 words that, when used with a specific mathematical operation, is able to restore all private keys and addresses associated with it. It gives full access to all assets in the addresses, so it should be kept in a secure place.
Block explorer
A website that has records of all transactions made on the blockchain and allows you to search for specific transactions or addresses, showing all relevant details about them.
Confirmed / Unconfirmed transaction
In the immediate seconds or minutes after a transaction is sent, a technical user could still alter or cancel the transaction. While it isn't mined into a block, a transaction is unconfirmed. It can be considered that the assets haven't yet left the sender's wallet. Only after it's mined into a block, the transaction considered confirmed. It is extremely unlikely that the transaction can be changed after confirmation, and each new block found after that makes any change exponentially harder.
Transaction ID / txid
A number that is unique for each transaction, allowing it to be immediately found on a block explorer once it's confirmed (and sometimes even before it confirms). Tapping any transaction in your Koala Wallet's history will show its ID, which also links to a block explorer.
Kadena chain
The Kadena blockchain consists of 20 individual chains, this is the ChainWeb. Your addresses have a specific balance in each of those chains.
Cross-chain transaction
A transaction that sends from one Kadena chain to another, for example from chain 0 to chain 19. Cross-chain transactions are composed of 2 parts, the initial transaction destroying the assets on the source chain, and the continuation one creating the assets on the destination chain. An incomplete cross-chain transaction can be completed afterwards.
Exchange / DEx / DeFi
An exchange is a service that allows trading from one digital asset to another, or between fiat and crypto currencies. DEx and DeFi stand for "Decentralized Exchange" and "Decentralized Finance" respectively. These are exchange or financial services that work via smart contracts, thus can work peer to peer without a centralized point of control or custody.
Gas
The amount of computation required to process transactions on chains like Kadena and Ethereum. Transaction fees are calculated based on how much gas the transaction uses.
EVM
Stands for "Ethereum Virtual Machine". A standard for executing computations created by Ethereum, and now used by several other blockchains.
NFT
Stands for "Non Fungible Token". Instead of normal tokens like USD, where every dollar is the same as every other dollar, NFTs are unique, individual and carry their own history. They can be made to be linked with art, music, club memberships etc.
Wallet / Hot Wallet
An online software that you control that connects to the internet to get the information (transactions, balance) about your addresses from the blockchain. It can build transactions, sign them (if it has the private keys) and broadcast them to the rest of the network. Custodial exchanges like Binance, Coinbase, etc may offer the option to send and receive, but since you don't control them, they are not wallets: they are accounts.
Watch-only Wallet
A wallet that watches the balance and transaction information for a given address just like a hot wallet, but has no private keys. This means it cannot send transactions by itself, but is also safe from nearly any hacking attempt since it has no secrets to keep.
Cold Storage / Cold Wallet / Hardware Wallet
A secure signing device that stores private keys in a completely offline way to minimize the attack surface. Since it doesn't have direct internet access to the blockchain, it receives transaction information from a watch-only wallet and returns the transaction signature without ever giving up the private keys.
Smart Contract
Computer code that exists on the blockchain itself, and can be published by anyone via special transactions. When executed, the code can transact coins and tokens based on specific instructions, making the money itself programmable.