Assuming you mean financial interest, it works like this:

You start with £100 which you have deposited in a bank.

You get 5% interest per year.

After the first year you have £105, that's 100 * (1 + 0.05)

After the second year you have £110.25, that's 100 * (1 + 0.05)^2

After the third year, you have £115.76, that's 100 * (1 + 0.05)^3

And so on.

The bank pays you interest in order to incentivise you to put your money in the bank. The bank can then lend this money out to other people and make a profit from the difference between the loan interest (that the bank gets from the person with the loan) and the savings account interest (that the bank pays out to you).

Banks help the economy by strongly encouraging everyone to lend their money somewhere useful rather than stuff it under a mattress and have it do nothing.

Obviously there's a lot more to finance. Has that helped? What specific thing were you confused about?

Because being choked is not just about restricting airflow, it is about restricting bloodflow.

Choking someone blocks the arteries that feed blood to their brain, and this is the mechanism that causes them to pass out.

it's an extremely cheap and simple computer that is mainly used for teaching (because you can realistically afford to buy one for every student, and they're cheap to replace if they're lost or broken). They also have some applications in embedded systems demonstrators (you can strap a battery to the bottom and move it around easily).