I was going through the following article , and thought had something to discuss:

/what-is-stock-investing.html

a) As per the article On what is stock investing,
Quote:

“Investment is where money is lent or spent on goods that would give high returns over a period of time.”
Unquote
When we speak of investment in a whole we never always make it for HUGE or big returns. We can make investments for security – like a Bank Deposit (whose return is typically low) for a steady and safe return. Well not blowing the fact that generally when we speak of Investments we expect high returns. So when we define Investments we cannot just tag it with a high returns as it is the purpose that can determine the rate of the Return. When rates of return are HIGH it demands higher risks. We should define Investment as per Wiki:
Quote:
“Investment is putting money into something with the expectation of gain, that upon thorough analysis, has a high degree of security for the principal amount, as well as security of return, within an expected period of time”
Unquote
Sources:
http://money.cnn.com/magazines/moneymag/money101/lesson4/index.htm

http://en.wikipedia.org/wiki/Investment

b) As per the article On what is stock investing,
Quote:
“ It is a unique property whose value fluctuates high or low based on the development of company”
Unquote
Whenever we talk about stocks and its price we all know that it cannot depend on a single factor which can determine the stock price. Development of the company, its future expectations and the present performance of the company all do play a role in stock determination but at times even a rapidly developing company’s stock can fall haywire. So we are right in saying that the stocks of a company depends on a combination of factors that influences the price. There are no set factors that influence the price of the shares – all are on based on various theories of valuation as no one can determine the actual reasons – all are assumptions. There can be a variety of reasons – like supply and demand, company’s future expectations, uncertainty, information etc etc. And yes there are various theories like efficient market theory (EMT) which also includes various other aspects as well.

Sources:
http://money.stackexchange.com/questions/10053/are-stock-prices-purely-or-mostly-only-based-on-human-action
http://www.stockscores.com/basics.asp?essayid=3