UK politics.

The UK is part of the European parliament, which controls international regulation and standardisation, translating into foreign relations and agreements in the UK.

The UK is made of four constituent countries: England, Scotland, Wales, and Northern Ireland. Northern Ireland is the northern portion of Ireland which wasn't separated along with the rest of Ireland.

Scotland, Wales, and Northern Ireland have national parliaments. (Holyrood, Senned, Stormont) The UK has a supranational parliament. (Westminster) England doesn't have a national parliament, or any form of national government, because England swamps the UK parliament, and has control over parts of the UK.

Some regions of England (but not all) have regional parliaments. The most well known of which is the London Assembly. Some individual counties (notably Cornwall) have councils that also function as parliaments to a limited extent.

Anybody in Scotland, Wales, or Northern Ireland can vote in their national parliament elections, but not eachothers, and other people in other parts of the UK can't vote in them, even if they're Scottish, Welsh, or Northern Irish.

Education in Scotland is free for Scottish citizens or non-UK citizens studying in Scotland. This is because for EU citizens studying in a country, the EU gives a monetary grant. The UK does not give a monetary grant to cover the cost of other UK citizens studying in Scotland. Education for Welsh citizens is free, regardless of where they study (including Scotland), but not for other citizens (including EU citizens) studying in Wales. The Welsh government pays for Welsh citizens to study regardless of where. All other UK citizens have completely privatised education, and have to pay £11k per year (for up to £44k for a full course. Ouch)

The crown dependencies (Mann, Jersey, Guernsey) aren't in the UK. They're governed by the UK because they belong to the Queen. They have their own separate governments. They aren't in the EU.

The overseas territories aren't in the UK, but are "of" the UK. They're governed by the UK, don't belong to the Queen (despite having the Queen as the head-of-state), each have their own local parliament, have no represenation in the UK parliament, and aren't part of the EU. Except for Gibralter, which is. For some reason. This is despite France's overseas territories being in the EU, including Guyana.

The UK parliament votes are 650 first-past-the-post seats. The Scottish parliament votes are 129 seats made up of 56 proportional representation seats across 8 regions of 7 seats each, using the D'Hondt method, and 73 constituency first-past-the-post seats. This system is deliberately convoluted, and was designed by labour with the express purpose of keeping the SNP out and making sure Scotland was always ruled by a coalition of Labour, the Tories, and the Lib Dems. That didn't work. The other national and regional parliaments are as or more convoluted than this.

The same parties generally stand in Wales, England, and Scotland, with the exception of parties that willingly limit themselves to a country (such as Plaid Cymru or the SNP). Northern Ireland's political landscape is rapidly different, with a subsection of parties from the UK (most notably UKIP), parties from the sovereign state of Ireland (Most notably Sinn Fein), and local parties. (e.g. Alliance) Parties in Northern Ireland are separated into Nationalist (seeking reunification with Ireland), Unionist (seeking to stay in the UK), and neutral. (taking no stance on the matter, or seeking independence, but not reunification with Ireland) Theoretically, you could have a party lead the Stormont parliament with a first minister of Northern Ireland who isn't a citizen of the UK. Conversely, the Irish parliament (the Dail) could have a party lead by someone who isn't a citizen of Ireland.

Council elections use different voting systems in different countries in the UK. In Scotland, they use the multi-member single-transferable-vote to elect two members per ward (subregion of a council area). In 2007, a council election and national election took place on the same day, leading to confusion as there were *three separate voting systems* in use - the D'Hondt regional system, the first-past-the-post constituency system, and the multi-member first-past-the-post system. Theoretically, en EU, National, UK, and Council election could all be held on the same day in Scotland, in which case, one citizen would have a national D'Hondt PR list vote, a regional D'Honst PR list vote, two constituency first-past-the-post votes for different constituencies that could cover rapidly different constituencies in terms of size, area, and population, and a two-member single-transferable vote. Irish citizens can vote in Westminster elections, but only Irish citizens (and not any UK citizens) can vote in Irish elections)

England, Northern Ireland, and Wales use the Common Law System (the same as the US, Australia, etc.) - Scotland uses the Civil law system. Scotland and Northern Ireland have separate legal systems, and England/Wales constitutes a single legal system. Northern Ireland's legal system is partially intertwined with Ireland's, a separate sovereign state.

UK politics is anything but simple.