Interesting .. so why not just put all countries on a " must apply " for visa .
Everyone applies for a visa to visit (unless they are British or are using EU laws) but citizens of some countries can apply for entry at the border.
Interestingly, EEA citizens and their non-EEA citizen family members are only allowed 3 months to visit the UK, as that is what the EU states. They don't get the up to 6 months under UK rules. If they overstay their visit, then they are in breach of UK immgiration rules - they are not using EEA rules and don't have permission to be in the UK under UK immigration rules.
Even some who get say a work visa for the UK have to report to the police when they arrive and tell the police as soon as they change address, if they are a country where the UK requires that. Citizens of the other countries who have a UK visa, do not have to report to the police.
In some EEA countries, they require all EEA citizens and their family members to register with the police it they are going to use the EU's free movement in their country.
Also say if you land in Ireland and stay in Ireland for the max of 90 days then fly to the uk and decide I'm gonna travel around for over 90 days because it says I can stay for 6 months I mean technically you're in a different country right ? So how does that all work ?
I dunno it just is all crazy to me
If you enter via Ireland, then you omly have 90 days to visit the Ireland and the UK. You can't then travel to the UK from Ireland and get up to another 6 months. There is no border bewteen Ireland and the UK and your 90 days that the Irish gave you, is for the UK too.
If you enter via the UK, then you get up to 6 months to visit the UK and Ireland. But remenber that the UK border officer doesn't have to give you 6 months as they could stamp you in for less time.
EDIT ksand beat me to it.