Vanguard is well-known for its low-cost stock-based mutual funds, and its index funds are some of the cheapest of all. Here's a list of Vanguard's current roster of index funds available as "investor shares" and the indexes they track so you can review your options and make the best decisions for your portfolio. What is an index fund? An index fund is a mutual fund or ETF that tracks a certain index, either through directly buying the stocks in the index, or through derivative instruments. For example, an S&P 500 index fund would own all 500 stocks in that index, in the same proportions. Image source: Getty Images. Index funds are also known as passively managed funds because their managers don't actually choose the stocks -- rather, they buy and sell based on the construction of the index. For this reason, index funds tend to have relatively low expense ratios when compared with actively managed funds, since those managers (theoretically) need to be skilled stock-pickers. Vanguard's large-cap index funds Fund Name Symbol Expense Ratio Yield 10-Year Annualized Total Returns Underlying Index Vanguard 500 Index Fund VFINX 0.16% 1.98% 7.30% S&P 500 Vanguard Dividend Appreciation Index Fund VDAIX 0.19% 2.01% 7.55% NASDAQ U.S. Dividend Achievers Select Vanguard FTSE Social Index Fund VFTSX 0.25% 1.76% 6.30% FTSE4Good U.S. Select Index Vanguard Growth Index Fund VIGRX 0.22% 1.26% 8.52% CRSP U.S. Large Cap Growth Index Vanguard High Dividend Yield Index Fund VHDYX 0.16% 3.02% 6.81% (since Nov. 16, 2006) FTSE High Dividend Yield Index Vanguard Large-Cap Index Fund VLACX 0.20% 1.89% 7.40% CRSP U.S. Large Cap Index Vanguard Value Index Fund VIVAX 0.22% 2.50% 6.24% CRSP U.S. Large Cap Value Index Data source: Vanguard. Vanguard's mid-cap index funds Fund Name Symbol Expense Ratio Yield 10-Year Annualized Total Returns Underlying Index Vanguard Extended Market Index Fund VEXMX 0.22% 1.25% 7.33% S&P Completion Index Vanguard Mid-Cap Growth Index Fund VMGIX 0.20% 0.65% 7.85% CRSP U.S. Mid Cap Growth Index Vanguard Mid-Cap Index Fund VIMSX 0.20% 1.36% 7.66% CRSP U.S. Mid Cap Index Vanguard Mid-Cap Value Index Fund VMVIX 0.20% 1.96% 7.86% CRSP U.S. Mid Cap Value Index Data source: Vanguard (Growth and Value fund returns are from August 2006 inception through 6/30/2016). Vanguard's small-cap index funds Fund Name Symbol Expense Ratio Yield 10-Year Annualized Total Returns Underlying Index Vanguard Small-Cap Growth Index Fund VISGX 0.20% 0.83% 7.87% CRSP U.S. Small Cap Growth Index Vanguard Small-Cap Index Fund NAESX 0.20% 1.41% 7.61% CRSP U.S. Small Cap Index Vanguard Small-Cap Value Index Fund VISVX 0.20% 1.86% 7.07% CRSP U.S. Small Cap Value Index Data source: Vanguard. Vanguard's total stock market funds Fund Name Symbol Expense Ratio Yield 10-Year Annualized Total Returns Underlying Index Vanguard Total Stock Market Index Fund VTSMX 0.16% 1.84% 7.86% CRSP U.S. Total Market Index Vanguard Total World Stock Index Fund VTWSX 0.25% 2.10% N/A (Inception June 2008) FTSE Global All Cap Index Data source: Vanguard. Vanguard's international stock index funds Fund Name Symbol Expense Ratio Distribution Yield (TTM) 10-Year Annualized Total Returns Underlying Index Vanguard Developed Markets Index Fund VDVIX 0.20% 2.65% N/A (inception Dec. 2013) FTSE Developed All Cap ex U.S. Index Vanguard Emerging Markets Stock Index Fund VEIEX 0.33% 2.26% 3.39% FTSE Emerging Markets All Cap China A Transition Index Vanguard European Stock Index Fund VEURX 0.26% 3.21% 1.74% FTSE Developed Europe All Cap Index Vanguard FTSE All-World ex-US Index Fund VFWIX 0.26% 2.66% N/A (inception March 2007) FTSE All-World ex-U.S. Index Vanguard FTSE All-World ex-US Small-Cap Index Fund VFSVX 0.31% 2.46% N/A (inception April 2009) FTSE Global Small-Cap ex-U.S. Index Vanguard International Dividend Appreciation Index Fund VIAIX 0.35% N/A N/A (inception Feb. 2016) NASDAQ Intl Dividend Achievers Select Index Vanguard International High Dividend Yield Index Fund VIHIX 0.40% N/A N/A (inception Feb. 2016) FTSE All-World ex-U.S. High Dividend Yield Index Vanguard Pacific Stock Index Fund VPACX 0.26% 2.22% 1.67% FTSE Developed Asia Pacific All Cap Index Vanguard Total International Stock Index Fund VGTSX 0.19% 2.64% 1.90% FTSE Global All Cap ex-U.S. Index Data source: Vanguard. Vanguard's U.S bond index funds Fund Name Symbol Expense Ratio Yield 10-Year Annualized Total Returns Underlying Index Vanguard Intermediate-Term Bond Index Fund VBIIX 0.16% 1.86% 6.29% Barclays U.S. 5-10 Year Government/Credit Float Index Vanguard Long-Term Bond Index Fund VBLTX 0.16% 3.14% 8.38% Barclays U.S. Long Government/Credit Float Adjusted Index Vanguard Short-Term Bond Index Fund VBISX 0.16% 0.99% 3.37% Barclays U.S. 1-5 Year Government/Credit Float Adjusted Index Vanguard Short-Term Inflation-Protected Securities Index VTIPX 0.17% -0.43% N/A (inception Oct. 2012) Barclays U.S. 0-5 Year TIPS Index Vanguard Total Bond Market Index Fund VBMFX 0.16% 1.79% 5.01% Barclays U.S. Aggregate Float Adjusted Index Vanguard Tax-Exempt Bond Index Fund VTEBX 0.20% 1.27% N/A (inception Aug. 2015) S&P National AMT-Free Municipal Bond Index Data source: Vanguard. Vanguard's international and global bond index funds Fund Name Symbol Expense Ratio Yield 10-Year Annualized Total Returns Underlying Index Vanguard Emerging Markets Government Bond Index Fund VGOVX 0.49% 3.93% N/A (inception May 2013) Barclays USD EmergMkt GovRIC Cap Index Vanguard Total International Bond Index Fund VTIBX 0.17% 0.41% N/A (inception May 2013) Barclays Global Aggregate ex-USD Float Adjusted RIC Capped Index Data source: Vanguard. Vanguard's balanced index fund (stocks and bonds) Fund Name Symbol Expense Ratio Yield 10-Year Annualized Total Returns Underlying Index Vanguard Balanced Index Fund VBINX 0.22% 1.76% 6.79% 60% CRSP U.S. Total Market Index, 40% Barclays U.S. Aggregate Float Adjusted Index Data source: Vanguard. Choosing the best index funds for you In a nutshell, the best index funds for you are those that fit into your specific investment objectives. For example, if you have a relatively low risk tolerance, a small-cap growth fund might not be the best choice for you. And, if you have nothing but U.S.-based companies in your current portfolio, an international index fund could help you get some much-needed geographical diversification. The point is that this list can serve as a good starting point, but you still need to do your homework and make sure the funds you choose can help you meet your goals. The $15,834 Social Security bonus most retirees completely overlook If you're like most Americans, you're a few years (or more) behind on your retirement savings. But a handful of little-known "Social Security secrets" could help ensure a boost in your retirement income. For example: one easy trick could pay you as much as $15,834 more... each year! Once you learn how to maximize your Social Security benefits, we think you could retire confidently with the peace of mind we're all after. Simply click here to discover how to learn more about these strategies.Matthew Frankel has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.