What is a one-sentence summary of the following article?
Investing in the stock market involves risk, and this includes the risk of permanently losing money. Before investing, always ensure you have your basic financial needs taken care of in the event of a job loss or catastrophic event.  Make sure you have 3 to 6 months of your income readily available in a savings account. This ensures that if you quickly need money, you will not need to rely on selling your stocks. Even relatively "safe" stocks can fluctuate dramatically over time, and there is always a probability your stock could be below what you bought it for when you need cash. Ensure your insurance needs are met. Before allocating a portion of your monthly income to investing, make sure you own proper insurance on your assets, as well as on your health. Remember to never depend on investment money to cover any catastrophic event, as investments do fluctuate over time. For example, if your savings were invested in the stock market in 2008, and you also needed to spend 6 months off work due to an illness, you would have been forced to sell your stocks at a potential 50% loss due to the market crash at the time. By having proper savings and insurance, your basic needs are always covered regardless of stock market volatility. Depending on your investment needs, there are several different types of accounts you may want to consider opening. Each of these accounts represents a vehicle in which to hold your investments.  A taxable account refers to an account in which all investment income earned within the account is taxed in the year it was received. Therefore, if you received any interest or dividend payments, or if you sell the stock for a profit, you will need to pay the appropriate taxes. As well, money is available without penalty in these accounts, as opposed to investments in tax deferred accounts.    A traditional Individual Retirement Account (IRA) allows for tax-deductible contributions but limits how much you can contribute. An IRA doesn't allow you to withdraw funds until you reach retirement age (unless you're willing to pay a penalty). You would be required to start withdrawing funds by age 70. Those withdrawals will be taxed. The benefit to the IRA is that all investments in the account can grow and compound tax free. If, for example, you have $1000 invested in a stock, and receive a 5% ($50 per year) in dividends, that $50 can be reinvested in full, rather than less due to taxes. This means the next year, you will earn 5% on $1050. The trade-off is less access to money due to the penalty for early withdrawal.  Roth Individual Retirement Accounts do not allow for tax-deductible contributions but do allow for tax-free withdrawals in retirement. Roth IRAs do not require you to make withdrawals by a certain age, making them a good way to transfer wealth to  heirs.   Any of these can be effective vehicles for investing. Spend some time learning more about your options before making a decision. While this may sound complex, dollar cost averaging simply refers to the fact that -- by investing the same amount each month -- your average purchase price will reflect the average share price over time.  Dollar cost averaging reduces risk due to the fact that by investing small sums on regular intervals, you reduce your odds of accidentally investing before a large downturn. It is a main reason why you should set up a regular schedule of monthly investing. In addition, it can also work to reduce costs, since when shares drop, your same monthly investment will purchase more of the lower cost shares.  When you invest money in a stock, you purchase shares for a particular price. If you can spend $500 per month, and the stock you like costs $5 per share, you can afford 100 shares. By putting a fixed amount of money into a stock each month ($500 for example), you can lower the price you pay for your shares, and thereby make more money when the stock goes up, due to a lower cost. This occurs because when the price of the shares drops, your monthly $500 will be able to purchase more shares, and when the price rises, your monthly $500 will purchase less. The end result is your average purchase price will lower over time. It is important to note that the opposite is also true -- if shares are constantly rising, your regular contribution will buy fewer and fewer shares, raising your average purchase price over time. However, your shares will also be raising in price so you will still profit. The key is to have a disciplined approach of investing at regular intervals, regardless of price, and avoid "timing the market". After a stock market crash, and before the stock market recovers (recoveries rise slower than crashes), consider increasing your 401k contribution by a few percent.  This way you will take advantage of low prices and not have to do anything else but stop the extra contribution a couple of years later. At the same time, your frequent, smaller contributions ensure that no relatively large sum is invested before a market downturn, thereby reducing risk. Compounding is an essential concept in investing, and refers to a stock (or any asset) generating earnings based on its reinvested earnings.  This is best explained through an example. Assume you invest $1000 in a stock in one year, and that stock pays a dividend of 5% each year. At the end of year one, you will have $1050. In year two, the stock will pay the same 5%, but now the 5% will be based on the $1050 you have. As a result, you will receive $52.50 in dividends, as opposed to $50 in the first year. Over time, this can produce huge growth. If you simply let that $1000 sit in account earning a 5% dividend, over 40 years, it would be worth over $7000 in 40 years. If you contribute an additional $1000 each year, it would be worth $133,000 in 40 years. If you started contributing $500 per month in year two, it would be worth nearly $800,000 after 40 years. Keep in mind since this is an example, we assumed the value of the stock and the dividend stayed constant. In reality, it would likely increase or decrease which could result in substantially more or less money after 40 years.

Summary:
Ensure investing is right for you. Choose the appropriate type of account. Implement dollar cost averaging. Explore compounding.