My Sister lives in London. My parents live in India and I am here in the USA. Different countries, different financial systems, and regulators. But some things are common. There are some tax-advantaged retirement accounts where employers can contribute and there is another form of retirement savings where you can contribute from your savings.
In the USA, they are known as 401k and IRA. In India, they are the Provident Fund and Public Provident Fund and in the UK they are pension funds and ISA (Individual Savings Account). Here we will talk about the UK, as the rules of contribution and withdrawal to these funds are different in different countries.