My apologies if the question seems basic.

I'm looking at their basic stats such as costs, but lost on where to find documentations that details these specific terms. I sent a message to Vanguard representatives and received a seemingly detailed reply:

Our Vanguard Total Stock Market Index Fund is now offered in two share classes: our conventional mutual fund Admiral share class (VTSAX) and our exchange-traded fund (ETF) share class, which trades under the ticker symbol VTI.

Vanguard Total Stock Market Index Fund had also been offered as an Investor Share class, which had a higher expense ratio, or cost, than its Admiral share counterpart, but had a lower initial investment minimum requirement. However, the Investor share class of Total Stock Market Index Fund has now been eliminated.

The Admiral share class of our Vanguard Total Stock Market Index Fund was previously available to investors with a $10,000 minimum investment. Now, you only need $3,000 to purchase into the lower-cost Vanguard Total Stock Market Index Fund Admiral Shares.

Vanguard ETFs, including VTI, have an initial minimum investment of the price of one share.

MUTUAL FUNDS AND ETFS>> Both the conventional mutual fund and the ETF share classes of Vanguard Total Stock Market Index Fund invest in the exact same companies.

Vanguard ETFs invest in domestic, international, and sector-specific stock and bond index funds, and cover a range of market segments, investment styles, sectors, and industries. The investment objective and policies for each Vanguard ETF are the same as corresponding mutual fund share classes, with one exception: ETF shares trade continuously on the stock exchange, and at market prices rather than net asset value.

Continuous trading allows you to buy and sell ETF shares throughout the day. Mutual funds, in contrast, are priced once daily after the market closes.

ETFs may trade at a premium or discount to their net asset value. The market price of an ETF is determined by the prices of the stocks and bonds held by the ETF as well as market supply and demand.

ETFs and conventional mutual funds have expense ratios--annual operating expenses--expressed as a percentage of assets. Expense ratios for most ETFs are lower than those for conventional mutual fund shares. This is because ETFs do not have recordkeeping expenses that conventional mutual funds have.

At Vanguard, you'll see this difference if you compare the conventional mutual fund with its corresponding ETF. For example: as of April 26, 2019, the expense ratio for VTSAX was 0.04%. On the other hand, the expense ratio for VTI was 0.03% as of April 26, 2019.

You can get more information about Vanguard ETFs including information on buying, selling, and pricing, at: https://investor.vanguard.com/etf/faqs

To learn about the differences between mutual funds and ETFs, please access the link below: https://investor.vanguard.com/etf/etf-vs-mutual-fund

Trading limitations, funds’ expenses, and a minimum investment apply. See the Vanguard Brokerage Services Commission and Fee Schedules on vanguard.com for full details, including limits and exclusions.

Vanguard ETF shares are not redeemable with the issuing fund other than in very large aggregations worth millions of dollars. Instead, investors must buy and sell Vanguard ETF shares in the secondary market and hold those shares in a brokerage account. In doing so, the investor may incur brokerage commissions and may pay more than net asset value when buying and receive less than net asset value when selling.

I felt that I should share this and call for a bit of help on deciding beyond the FAQ. It would be appreciated.