Please see this other thread
which discusses the topic in more detail.
It is an important topic. The way that you earn a living has a powerful effect because it the kamma that you are doing every day.
Even if your livelihood is not immoral or wrong-livelihood according toe the strict definition of the texts, it still has a significant effect on your future happiness.
In our modern materialistic society, there are many ways of earning a living that depend on encouraging foolishness, and the endless pursuit of sensual pleasures. It may be perfectly lawful and not immoral pleasures, but it is not a wholesome livelihood.
The ideal livelihood would be one that encourages wholesome kamma such as giving charity, observing morality, learning, or the development of wisdom.