Sore wa = That is
For example
A. Sore wa nan desu ka (What is that?)
B. Kore wa hon desu (This is a book)
You can also find kore wa and are wa, the difference is the distance from the object
Kore (This) > when the object is within your reach
Sore (That) > is when it's not within your reach but near someone else you're talking to
Are (That) > is when the object is far from you and your companions