Bitcoin as a network and an asset
Bitcoin can refer both to the network and to the digital asset BTC. The network records transfers under a public set of rules, while BTC is the unit used within that system.
Supply and issuance
The protocol defines limited issuance and a schedule for creating new units. Changes in the block reward, known as halvings, are part of those programmed rules.
Mining and proof of work
The network uses proof of work. Miners compete to propose blocks and contribute computing power to the consensus process.
What is useful to learn
To understand Bitcoin, it helps to study keys, addresses, blocks, fees, confirmations and the role of nodes. Understanding those concepts is different from analyzing its price.