U.K social security eligibility

In the USA one needs to have accumulated 40 credits in order to become eligible for social security. Does the UK have a similar credit system? What are the eligibility criteria for UK social security? Also, can the UK social security money be received anywhere in the world?

Social security in the USA is a government pension that one can choose to receive any time after age 62. For this pension, one needs to pay a certain percentage of one’s annual wages (typically, 6%-7%) as social security tax. For every $1560 of wages in a given year one gets 1 credit for that year, and one can get up to 4 credits per year. One needs to accumulate 40 credits in order to receive this pension. The actual monthly amount of the pension depends on the average of one’s wages when the credits were accumulated. There is some complex formula that they use to determine the amount of this pension.

The later one chooses to have this pension started, the more is the amount of the pension. This is like a defined benefit pension plan (benefits are promised and the responsibility to invest the money in the social security funds lies with the government). Apart from this, one can invest one’s pre-tax dollars in a defined contribution plan (responsibility for where to invest lies with the contributor and benefits are not promised) such as the traditional IRA and the employer sponsored 401(K) with the money being taxed only when withdrawals are taken from the plan, and can invest one’s post-tax dollars into a Roth IRA where they are never taxed – not even at withdrawal. Are there any British equivalents to these?