Can I get A Clear Idea About ISBLANK AND ISNUMBER??

Hello@Meenambigai C,

• ISBLANK():- Determines if an expression has a value and returns TRUE if it does not. If it contains a value, this function returns FALSE.ISBLANK (salesforce.com)
• ISNUMBER():-Determines if a text value is a number and returns TRUE if it is. Otherwise, returns FALSE.ISNUMBER (salesforce.com)