How does one "transfer" SOL to another account, rather than using a "transaction"?

Question

What is the difference between a transaction and a transfer? From my understanding so far, and according to the answer provided in this question, transactions are meant for exchanges using native SOL, and transfers for spl-tokens transactions are for anything that needs to be written on the blockchain, and a transfer is an instruction that can be included in a transaction (as clarified to me in the comments, thank you @xenoshiba).

But when I look at some accounts on an explorer like solana.fm, I sometimes see SOL being sent to another account under the "transfer" section rather than the "transaction" section, as shown in the picture below to clarify:

How does one "transfer" SOL to another account (instead of using a "transaction") when using the JavaScript client and libraries @solana/web3.js and @solana/spl-token, like in the picture above?

Answer 1

As tymur999 said: A transfer is a special type of transaction that only changes the SOL balance of two accounts or the balance of two token accounts (one sender and recipient).

From Solana's point of view, transfers aren't treated differently than any other type of transaction that does more or less things. SolanaFM and other block explorers just showcase them differently to make it easier to read for non-technical people & so that if your account is getting spammed by other transactions (e.g. spam NFTs) you can still efficiently find "real" transfers you care about.

You also asked how to execute a transfer in javascript. Here's how to do it for spl tokens and here's how to to do it for sol.