A phone screen is two layers glued together: the glass you touch and the display underneath. On most current phones they are replaced as one part, but what you see tells us how bad the damage is (sample note).
If the picture is perfect and touch works everywhere, only the glass is cracked. You can keep using it for a while, with a screen protector over the cracks so they do not spread or cut a finger.
Lines, black or green patches, or touch that stops working in one area mean the display is damaged too. Book a repair before it spreads; the price is the same either way.