what is meant by ordinary business of life ?

In our ordinary business of life,we come across the problem of choice in a lot of situation.We all  have limited resources which we have to utilise in a way that we get maximum satisaction.there are million ways and rather million consumption bundles which we can give us infinite satisfaction but what  makes this optimisation problem sensible are  constraints.For instance we can buy a table or a sofa or a set of chairs or chest of drawers .So we have to make a choice!1 SO constraints arise the situation of choice and we face it regularly  .Hence economics is the study of  man in the ordinary business o life