How can I interpret this scatterplot? Please help me to interpret this graph in terms of correlation type. Which type involves two vectors in directions observed below (see graph screenshot)? Thanks in advance.

 A: Assuming the dots are your observations, the vectors seem to express upper and lower bounds on the range of $y$ as a function of $x$. The correlation appears weakly negative at a glance, but I wouldn't really trust my eyeballs to estimate Pearson's $r$. What does seem clear enough is that $y$ exhibits heteroscedasticity across $x$. Wikipedia's Consequences section may be of further interest to you. See also for comparison 
Wikipedia's plot with random data showing heteroscedasticity: by Q9.
Like most distributional characteristics, heteroscedasticity is a matter of degree, and few real datasets are truly, absolutely homoscedastic. Despite my own behavior here, you may not want to "eyeball" a scatterplot for heteroscedasticity any more than for a correlation. Many tests of homoscedasticity exist, including levenes-test. Fixes are available, but the best may be robust methods that tolerate heteroscedasticity. This is not to say heteroscedasticity is only a data-analytic nuisance – it may also be of focal theoretical interest. An example from Wikipedia describes wealth and diet variability:

A classic example of heteroscedasticity is that of income versus expenditure on meals...A poorer person will spend a rather constant amount by always eating inexpensive food; a wealthier person may occasionally buy inexpensive food and at other times eat expensive meals. Those with higher incomes display a greater variability of food consumption.

Interested readers may wish to check the tag wiki for heteroscedasticity; I've edited in more info like this.
