Meaning of investment is different in finance and economics. As an economics term, investing is the accumulation of newly produced physical entities, such as houses, machinery, factories, and goods inventories.
In finance, investing means putting money into an asset (property, gold, stock,..) with the expectation of capital appreciation, dividends, and/or earning interest. This action may or may not be backed by analysis or research. Most forms of investment involve some type of risk, such as investment in properties, equities, fixed interest securities may be subject to risk of inflation. Stock prices may drop, prices of things invested on may fluctuate, company holding investor's commodities may default (not keep its promises), laws in the country or state may change which may add tax on invested items, or block sales of those items. When we talk about investing we usually mean the second term, namely financial investment.
Financial investing is in other words purchase of an asset with the hope that it will generate income or become more valuable and sell at a higher price. Government bonds are considered to be long term, low return, safe investments (but things may be different in high inflation situation). International stocks may offer short term high risk investing options, which may be called speculation.
Warren Buffett is considered to be the most successful investor of all time. He is the first or the second richest person in US according to Forbes billionaire list. There are other richer people (bankers), we mean much much richer than Bill Gates or Warren Buffett who may be referred to as "better" investors. An investor should do an investment plan, but things may not happen as expected so there must be a good investing strategy, which should include diversification of portfolio. For example a certain percentage of money should be put into precious metals like gold, silver, platinum, palladium, as an insurance policy against things like inflation. Although precious metals don't bring any return directly, in case of high inflation they may bring a reliable liquidity.
Invention of computers and internet bring significant simplification when investing on or selling various asset types, but this also makes cheating and speculation easy, especially in case of lack of sufficient regulation. This is said to be the case of derivative market. Derivative products are things derived from usual financial products but are more complex and not easy to understand. One example is credit default swap. There is some emotional side of investing and some big players may try to take advantage of this fact. For example when prices of something increase people start buying, when prices drop people start selling not to sell last. This may lead to some irrational consequences. Some others will say, the best time to invest is when everyone is selling; and they may claim they know what is worth investing on. Of course they may be right or wrong. You have to guess,or spend time to do you research.
We may add a third meaning into the word investing; namely its daily use; such as investing in health (getting a good health insurance, eating healthy organic foods, exercise), investing in building a career (college education, phd, MBA, attanding conferences, publishing articles on journals.).
An economic crisis may affect a nation as a whole, or may be present globally. Prices may go up and up and up and form, what is called, a "bubble", and then suddenly burst. Some consider a crisis situation as an opportunity and take their and their clients' position accordingly. Since it may not be obvious if something may be considered as a bubble, or when the bubble would be burst, short term plans may fail, even those made by expert investors. Diversification is the key in a good investment strategy. Even investors who say stockmarket is bubble and gold will skyrocket admit that they 'gamble' on stockmarket, and don't put more than 20 percent into gold.