Science when used in practical life for our utility is 
named as technology and when this technology is to be used 
in real life, there will certainly be generation of 
constraints in the path of execution like there will always 
be bottlenecks, some amount of inefficiency, lower 
productivity, human errors etc. or at least the chances of 
these. management is the study to deal with those obstacles 
and bring out the best solution out of it.

in other words, 

we eat omlets, the hen is "science" which gives us the egg, 
egg can be taken as "technology" which is derived 
from "science." But we couldnt have eaten the egg in its 
raw form or else it wouldnt have been so tasty, therefore 
we fry it and make omlet to eat the content more easily, 
this frying process is called "management"