In ethereum network how data structured and is every data stored, is public?

Question

Let's say, 3 companies are using ethereum network.

1. Company A
2. Company B
3. Company C

Company A put some data, block01 and block02. So ethereum network looks like,

Genesis Block -> block01 -> block02

Now Company B put another piece of data block03. So the chain looks like,

Genesis Block -> block01 -> block02 -> block 03

Here come the Company C and this company put bock04 and block05

So finally the blockchain is like

Genesis Block -> block01 -> block02 -> block03 -> block04 -> block04

Am I right about the blockchain architecture?

Also, all the data stored in the block, are they visible to all? Can anyone check the data inside block in the ethereum network?

Answer 1

All the data is visible for everyone who has access to the blockchain. If it's a private blockchain you can control who has access to it.

Your idea about the architecture is approximately correct with the addition that usually data is added in parallel so different entities' data get added in the same block. Different entities don't typically "wait" for other entity to end their data input.