Kadena is a Proof-of-Work (PoW) blockchain much like Bitcoin. This means miners must spend real energy in the real world to mine blocks and confirm transactions. However, Kadena splits its blockchain into 20 chains allowing the network to scale laterally. Each of these chains has a block time of 1.5 seconds, and each chain references 3 other peer chains in a specific pattern. This increases the overall security, making malicious miner attacks more expensive and less likely to succeed.
Kadena's 20 chains and their reference graph (source)
It's important to be mindful of the source and destination chains when transacting. Your account has a specific KDA balance on each chain. When someone wants to receive assets, they should inform you which chain they want to receive in. It is possible to send KDA from one chain to another, your Koala Wallet takes care of this process automatically.
Kadena accounts can natively have a human readable or "vanity" name (like "Alice" or "Jennys Burrito Shop"). With it you don't have to remember long unintelligible strings of text. Each account is controlled by one or more private keys. By default, your account's name in Koala is "k:" followed by the public key associated with the single private key that controls it. This makes wallet backup and recovery more simple and robust. Currently Koala Wallet doesn't allow sending to account addresses in a different format.
Transactions in Kadena must pay network fees to be processed. These fees depend on how much "gas" is used by the transaction (think of gas as how much processing must done by the miners). The Kadena developers have set up "gas stations" so that users can make transactions for free. Koala Wallet automatically takes care of calculating how much gas a transaction needs, determines the fees appropriately, and uses gas stations whenever possible.