Investors can find plenty of great exchange-traded funds (ETFs) to generate income. Which Vanguard ETFs offer the highest dividend yields? The SEC yield, by the way, is a metric developed by the SEC to help investors compare funds.

While all ETFs are different, there are two Vanguard funds I personally own and plan to continue buying for decades. An S&P 500 ETF tracks the S&P 500 ( ^GSPC 1.00%), meaning it includes all the stocks within the index. These stocks come from 500 of the largest companies in the U.S. across all corners of the market.

Its smart to seek income from your investments -- whether it's because you need that income to support yourself in retirement, or whether you want to use it to invest in more stocks. It's also a fine idea to seek that passive income from exchange-traded funds (ETFs) that are focused on dividend-paying shares.