LIBERAL AND LEFT WING

Liberalism is a broad concern with human liberty. It is a belief that individual decision-making is important and that, insofar as it is possible, people should be free to control their own lives. Liberals tend to believe that the only good reason for coercing a person - preventing them from taking a course of action - is to protect the rights of others.
Liberalism rejects the notion that we need to be commanded from above by wiser, cleverer, richer, more powerful, more articulate or more organized groups; instead, liberalism favours free association and voluntary arrangements wherever possible.
'Left' is a broad political term which has changed in meaning over the period of its use. I think it's fair to characterise 'left-wing' as 'concerned about improving the conditions of those who are suffering most from the present arrangement of society'. Yes, that's a long-winded way of saying it, but it's better to be long-winded than to leave anything open to interpretation.
So, a left-wing perspective on economic issues might involve concern about poverty, or the status of mistreated workers, or the effects of imbalances of power on those with the least power to control their own lives.
Left-wingers are primarily concerned with promoting the interests of the weak.