Investing can be for anyone, but that doesn't mean everyone will be comfortable picking individual stocks. You might not have the time, desire, or knowledge to research and purchase a portfolio of individual stocks, and track them over time.

Exchange-traded funds (ETFs) are a great tool for investors who'd rather not do all that portfolio-building work. These funds hold large collections of stocks, bonds, or other commodities, but trade under a single ticker symbol. There are funds that follow all the major indexes, and others that cover specific industries and investing styles, so you can easily build a diverse portfolio using them. Here are three great Vanguard ETFs that, when held as part of a diversified portfolio, could help you retire comfortably.

An all-encompassing fund

If wide diversification is your goal, the Vanguard Total World Stock ETF (VT 1.04%) might be for you. Owning this fund means investing in the global economy. Its portfolio includes a broad mix of stocks of both U.S. and foreign companies, as well as companies from both developed and emerging markets. The fund's top holdings include mega caps like Apple, Amazon, Johnson & Johnson, and UnitedHealth.

Every ETF charges fees to its investors for managing its portfolio, annually deducting a small share of the value of their investments. The total percentage of those fees is defined as the expense ratio, and Vanguard's tend to be extremely low. The Total World ETF, for example, has a very modest expense ratio of just 0.07%, so investors will keep nearly all of their returns. Additionally, you'll get some income when you own this ETF. The fund pays a dividend that yields a solid 2.8% at the current share price.

Just keep in mind that the fund does have exposure to more volatile markets. Non-U.S. companies make up roughly 41% of its holdings, and emerging markets account for 10%. The fund has averaged 8% annual price gains over the past decade.

A fund for the next bull market

The past 18 months have been rough for growth stocks, but the market moves in cycles, and those companies should eventually start to rise again. When that time comes, the Vanguard Small Cap Growth ETF (VBK 1.18%) might outperform. It focuses on smaller growth stocks, which can outrun the market when investor sentiment is on their side.

The fund is great for getting that potential upside exposure without doing all the homework yourself. No single stock makes up even 1% of the total fund, meaning that your investment is spread out from day one. Its largest holdings include Fair Isaac, Axon Enterprise, and Targa Resources. I find the expense ratio of 0.07% particularly attractive given the work it would take to follow all the companies in its portfolio individually.

You can expect that this fund will be pretty volatile. It only returned an average of 0.79% annually over the past three years, but its annualized returns over the past decade averaged 9.26%. In other words, it's a feast-or-famine asset that could deliver solid returns when market sentiment shifts back to favoring growth stocks.

Protect your retirement funds from inflation

If you've already built your nest egg nearly to your target size and now just want to get to retirement with your assets intact, the Vanguard Short-Term Inflation-Protected Securities ETF (VTIP 0.07%) might be what you need. The fund holds a collection of Treasury Inflation-Protected Securities (TIPS). These are U.S. Treasury bonds for which the principal is adjusted up or down based on the rate of inflation.

The fund's bonds have an average duration of 2.3 years, so investors considering this fund can have a short time horizon. Perhaps you're about to retire or need a stable place to park your money. The fund hasn't typically been very volatile over the years. The market price of the fund's shares is down 6% over the past decade, and that's because 2022 was one of the worst years for bonds in history.

The investment returns on this fund come almost solely from its dividends. The fund's yield is 6.7% right now, which is a heck of an income stream compared to most savings accounts. The fund's expense ratio is also meager at just 0.04%. Again, this can be a great option if you've already built the nest egg you'll need and want a conservative place to keep your money.