1. لماذا نستخدم الـ IP Address وليس الـ MAC Address ولو في حال لاينفع إستخدام الماك لماذا ؟ إشرح العملية الخاصة بهذا الأمر ؟

Because IP addresses are work with Routers which are layer3 devices in case of WANbut MAC addresses work with switches which are layer2 devices in case on LAN.

IP addresses work as Source and destination IPs but MAC addresses work as hop-to-hop.

That's why when tranferring traffic between a source and destination IP addresses take place and not MAC addresses.