Representatives from big-name tech companies Facebook, Google and Twitter faced a grilling on Capitol Hill this week over questions about how Russian operatives were able to use ads on their platforms to influence the election. But another name that you may never have heard of popped up among the discussion of these ads: Qiwi.

Here's a quick rundown of what Qiwi is and how it's involved in this issue.

What is Qiwi?

Qiwi is one of Russia's most widely used payment systems. It's similar to PayPal. Qiwi operates in Russia and other countries in the Commonwealth of Independent States, such as Ukraine, Belarus, Moldova and others.

Qiwi is publicly traded in the United States on the Nasdaq index.

How is it related to Russian election ads?

As The Washington Post has previously reported, many of the ads placed by Russians aimed at affecting the U.S. election were paid for through Qiwi.

Who uses Qiwi?

According to a 2016 survey of online payment services in Russia, Qiwi was the third-most-widely-used payment platform in Russia, behind Russian tech giants Yandex and WebMoney but ahead of PayPal. According to its most recent earnings report, the company processed $3.7 billion in payments in its most recent quarter.

The firm has specialized in enabling Russian citizens -- who, analysts say, are often distrustful of banks -- to make payments without having to use cash. The company built its reputation and user base through payment kiosks but has since been transitioning to mobile payments.

It is a relatively easy way to send money internationally, and therefore may have been a convenient tool for Russians looking to place advertisements.

How does Qiwi's involvement affect Americans?

Assuming you're in the United States, chances are you haven't really used Qiwi, unless you're sending money to or from Russia.

But the company has partnered with credit card giant Visa on a virtual wallet since 2011, which users can fill with money from their Qiwi accounts. There are approximately 18.5 million Visa Qiwi wallet accounts; they have emerged as a relatively easy way for Russians to send money across borders.

Visa did not immediately respond to a request for comment on whether its wallet has been used to purchase political ads through Facebook, Twitter or Google.