The total supply of Bitcoin is capped at 21 million coins, which is a limit set by its underlying algorithm to ensure scarcity and help control inflation. As of now, there are approximately 19.3 million Bitcoins in circulation. This means most of the Bitcoin that will ever exist has already been mined.

Bitcoins are released as rewards to miners who confirm transactions and add them to the blockchain. This process is known as mining. The reward for mining a block started at 50 Bitcoins and is halved approximately every four years in an event known as the "halving." Currently, the mining reward is 6.25 Bitcoins per block, and it will continue to decrease until the maximum supply of 21 million is reached around the year 2140. After this, no new Bitcoins will be created, and miners will be compensated solely through transaction fees.

Bitcoin mining is the process by which new Bitcoins are introduced into circulation and the network is secured and transactions are verified. It is also a critical component of the maintenance and development of the blockchain ledger. Here’s a detailed explanation of how it works:

1. Verification of Transactions

Miners use their computational power to verify groups of transactions, which are then compiled into blocks. These transactions need to be verified to prevent issues like double spending.
 

2. Formation of a New Block

Once transactions are verified, they are compiled into a block. The miner then works to add this new block to the blockchain. Each block includes a reference to the previous block, linking them in a chain, hence the term "blockchain."
 

3. Solving the Proof of Work

To add a block to the blockchain, miners must solve a complex mathematical puzzle known as proof of work. This requires extensive computational power. The first miner to solve the puzzle gets the right to add the block to the blockchain.
 

4. Receiving the Block Reward

Upon successfully adding a block to the blockchain, the miner receives a block reward, which as of the latest halving event, is 6.25 Bitcoins. This reward halves approximately every four years in an event known as Bitcoin halving.
 

5. Network Security

The process of mining also secures the Bitcoin network. The computational power required to solve the proof of work puzzle prevents malicious actors from easily altering the blockchain. If an attacker wishes to alter a transaction, they would need to redo the proof of work for the target block and all blocks after it, which is computationally expensive and practically infeasible as it would require majority control of the network’s mining power.

Storing Bitcoin securely is crucial given its value and the fact that transactions are irreversible. Here’s a guide on how to store Bitcoin:

1. Choose the Right Wallet

There are several types of wallets you can use to store Bitcoin, each offering different levels of security and convenience:

• Hardware Wallets: These are physical devices that store your private keys offline. They are considered the most secure form of Bitcoin storage. Examples include Trezor and Ledger.
• Software Wallets: These are programs that you can download to your computer or smartphone. They are more convenient for frequent transactions but are potentially vulnerable to online threats. Examples include Electrum and Exodus.
• Paper Wallets: This involves printing out your private and public keys on a piece of paper, which you then store in a safe place. It’s a form of cold storage and is secure from online threats but can be lost or damaged.
• Web Wallets: Also known as online wallets, these are hosted by a third party and accessible via the internet. They are convenient for frequent traders but are less secure since the third party controls the keys. Examples include wallets provided by exchanges like Coinbase or Binance.

2. Backup Your Wallet

Back up your wallet to protect against computer failures and human errors. For software and mobile wallets, this often means writing down a recovery phrase (12-24 words generated by your wallet). Store this phrase securely in a location separate from where you keep your wallet.

3. Use Strong Security Measures

• Encrypt Your Wallet: Use a strong password to encrypt your wallet, protecting your funds against unauthorized access.
• Use Two-Factor Authentication (2FA): Enable 2FA on any service that supports it to add an additional layer of security.
• Keep Software Updated: Regularly update your wallet software to protect against security vulnerabilities.

4. Consider Your Needs

• For daily use: Consider keeping a smaller amount of Bitcoin in a more accessible, possibly less secure wallet.
• For savings: Store the majority of your Bitcoin in a more secure environment, like a hardware wallet or another form of cold storage.

5. Secure Your Environment

• Physical Security: If using paper or hardware wallets, consider safe storage options like a safe deposit box or a personal safe.
• Cybersecurity: Ensure your computer and any device handling cryptocurrencies are free from malware and secured against potential threats.

By following these tips, you can significantly improve the security of your Bitcoin holdings. Each storage method has its trade-offs between security, convenience, and cost, so your choice depends on how much Bitcoin you're handling and what you intend to do with it.