Why do antibiotics not work against viral infection ?

How do antibiotics function ?

What are antibiotics? How they act against pathogens (bacteria)?

Why do soaps not work in hard water ?

Why do animals move ?

Why do organisms need water ?

Why antibiotic do not affect cough and cold ?

The meanings of 'antibiotics' is 'against life', whereas with reference to humans, they are 'pro life'.Substantiate the statements with suitable example.