Have you even though that some labels of the fields, tabs and headers are not suitable for your situation? Actually, all of them can be changed.
In SAP Business One, an authorized user is able to change most of these labels based by pressing the CTRL key and double click.
For example, if I want to change the Name into Company Name to make it more specific, I need to move my mouse on label Name, hold the CTRL key and double click. A window will show up and I can check it to whatever I what. I can also change the format, bold or Italics, in the window.
Then click Update, and the system will change the tag of A\P Invoice instantly.