orphan blocks

[FabioCarpi]

I has thinking...
The orphan blocks stay in everyone's machine?
I read, after 100 blocks, the branch is abandoned...
The biggest branch wins.
And all the transactions in the abandoned branch, need to  reconfirmed in the winner branch?

[hexafraction]

And all the transactions in the abandoned branch, need to  reconfirmed in the winner branch?

Yes, they will either be dropped, or will need to be confirmed by being added to blocks on the main branch.

The orphan blocks stay in everyone's machine?

Depends on the client, an SPV node probably won't keep them around, but a full node may need to keep them around in case that chain subsequently becomes longer again.

[Buffer Overflow]

I read, after 100 blocks, the branch is abandoned...
The biggest branch wins.
And all the transactions in the abandoned branch, need to  reconfirmed in the winner branch?

Transactions in the abandoned branch can be put inside other branches immediately. No need to wait 100 blocks.