I am a beginner in Solana Development and I recently learned that data in Solana blockchain can be stored inside accounts. Instead of this is it possible to store the data directly in a block instead of the account? For example, if I have a string, can I directly store it on a block as a transaction or some other way? If yes can you please tell me how? If not, then can you please tell me how can I make the account data immutable?
I will be really very grateful if you can help me out with this
While the accepted answer indicates No, it depends on your use case:
You actually can store data on chain vis-a-vis the transaction you submit. When you submit a transaction the entire content of the transaction is stored on the chain. You could then fetch that transaction, parse out the bits you want and you will have your data.
Shortly No
Transactions are stored in the block. Transactions are called public ledger and a ledger means a record of a business's financial transactions.
If the program needs to store state between transactions, it does so using accounts. Accounts are similar to files in operating systems such as Linux in that they may hold arbitrary data that persists beyond the lifetime of a program. Also like a file, an account includes metadata that tells the runtime who is allowed to access the data and how.
Unlike a file, the account includes metadata for the lifetime of the file. That lifetime is expressed by a number of fractional native tokens called lamports. Accounts are held in validator memory and pay "rent" to stay there. Each validator periodically scans all accounts and collects rent. Any account that drops to zero lamports is purged. Accounts can also be marked rent-exempt if they contain a sufficient number of lamports.
there are two types of accounts in solana: Executable and non-executable. Non-executable contracts store data or state of logic in your contract and htis has an owner. Owner can mutate the state. when you create an account, you assign an owner and later when your contract needs to access to that account, your contract checks if it is the owner or not owner
Executable accounts are immutable. Smart contracts in Solana are executable accounts, therefore once you deploy it you cannot mutate it
owner argument. You will be creating a publickey to assign it as an owner.