So I am pretty new to ethereum and development, one of my discoveries was MyEtherWallet. My question is how does the keystore file enable you to interact and use the blockchain. The keystore file obviously needs to have enough information so that it can retrieve your details. So my understanding is that it is a Json file containing details relevant to your account, when going through a specific process to then access your details. I need a better understanding of this process, or just an explanation of the contents contained in the keystore file. Any additional explanation or resource will be much appreciated. Again, I am a fairly new to ethereum.
At the bare minimum, the keystore file contains your private key. It may also contain your public key and address (both of which can be derived from the private key). Recall that the blockchain's information is public. Knowing your address allows you to filter transactions to show those involving your account. Knowing your private key is required to sign transactions. That is, the address allows you to read relevant information from the blockchain while the private key allows you to write information to the blockchain. See also What is the difference between a private key, password, brain wallet, and recovery passphrase?