The SAP End User License Agreement (commonly called the EULA) is an agreement that everyone who uses SAP Business One will need to sign.
In summary, the agreement states that you understand that you are not buying the rights to the software, rather the rights to use the software. By signing the agreement you acknowledge that you will not resell it or use it outside of the agreement terms listed in the document.
Note: You only need to sign the EULA if you are new to SAP. If you already have SAP and are just switching SAP service providers, you do not need to resign the EULA.