There are many links between wealth and power, those these links vary from country to country.
In a democratic country like the US, there are links between wealth and power because wealth can be used to help gain access to power. Wealth can be used to contribute to political campaigns, thus making large donors able to "have the ear" of politicians.
Wealth is also power because it can buy most things that it wants. Those who have money are typically able to pay people to do things that they really want done. Money can't buy everything, but it can typically buy many things that people want.
Wealth can also lead to future wealth and power. In the US, people with wealth have access to better education for their children. They live in places with good school systems or can pay for private schooling. Their children will get into good colleges because they have gone to the right schools and have the right experiences.
In these (and other) ways, wealth is linked to power in the near and long terms.