What is the use of 'Matter'
The following two special uses of 'Matter' are very common -(A) Noun -
'What is the matter?' means 'What is the trouble?' or 'What is the difficulty?'
'What is the matter with your ears?' means 'What is wrong with your years?'
(B) Verb -
'It doesn't matter.' means 'It is not important.'
'It won't matter.' means 'It will do no harm.'