Pass Textbox Value to an Active Form in Datagridview

Question

Hello Everyone, I hope someone could help me with my problem. Assuming I have 2 Forms namely: Form1 and Form2. Form1 has an empty datagridview in it while Form2 has a textbox in which carries a value to be passed in Form1's datagridview. Now, the thing I want to happen is, Form1 is always active while Form2 is carrying many values and inserts many rows depending on how many values inputted from the textbox in Form2. Can someone tell how me how it does? Thanks :)