A Bitcoin (BTC) can be divided into smaller units, just like other currencies. The smallest unit of Bitcoin is called a Satoshi, often abbreviated as sat. Bitcoin cannot be divided into smaller units than a Satoshi. One Satoshi is equal to 0.00000001 BTC (one hundred millionth of a Bitcoin). In other words, there are 100,000,000 Satoshis in one Bitcoin. However, it is not certain that a Satoshi will remain the smallest unit of Bitcoin. A software update could potentially change this situation.
The name Satoshi is derived from the anonymous creator of Bitcoin, Satoshi Nakamoto. It is still unclear whether this is a single person or a group of people.
Since Bitcoin can be divided into such small parts, it is easy to purchase Bitcoin and become part of the Bitcoin community. Some people still believe they need to buy a whole Bitcoin, but it is possible to buy a fraction of a Bitcoin on a cryptocurrency exchange.
Here are the Bitcoin units in relation to Satoshi: