How and why did technological developments play an important part in twentieth-century wars?

technological developments played an important part in twentieth century wars because it gave some sides an edge.

For example:

during WW2 an a machine was created to crack codes that Natzis were sending to each other, this led the sides fighting Hitler an advantage since they would be knowing what would be sent to other Natzis. This led to them being able to know what their next move would be.