No, they are European citizens.
No, there is no need to have visa traveling to EU countries. But in countries like Russia, Ukraine, Belarus British may need some additional permissions.
Yes
Yes. It is possible for a UK citizen to buy property and live in the other countries of Europe such as Spain without visa and permit.
Yes, you generally need a visa to work in the UK if you are not a British citizen or a citizen of a country within the European Economic Area (EEA) or Switzerland.
Yes, you can work in the UK without a visa if you are a British or Irish citizen or have another eligible immigration status that grants you the right to work. Most other foreign nationals, including Indian citizens, need a valid work visa or appropriate permission before starting employment. Requirements depend on your nationality and immigration status. Planning to work in the UK? Welkin Migration can help you explore suitable UK work visa options and guide you through the application process.
not for a holiday
yes
you cannot go to every country of Europe without any visa and permit even if you are a citizen of UK. Also,you cannot do business and buy any property in the whole Europe without visa and permission.
Yes, you will need a visa to enter the UK if you are not a citizen of a country that is part of the European Union or European Economic Area.
Yes
She would need a UK work visa.
No, Serbian citizens doesn't need visa for Schengen countries, but they need visa for UK and Ireland.