Explain this Entity Relationship Diagram in very spesific detail.

Customer HPK Product Supplier PK Supplier ID Supplier name Supp. surname Supp, location email tel Fax Customer ID Customer name Customer surname Gender Tel.no email Country Order Brand HPK Model Model no Production location Year of release Price Sales PK ID FK Model FK Supplier ID Cost/unit Price/unit Qly sold Date sold Revenue Profit PK Order no FK Customer ID Customer name Customer surname Country OFK Model Quantity Unit price Date sold Total price Tracking no Customer HPK Product Supplier PK Supplier ID Supplier name Supp. surname Supp, location email tel Fax Customer ID Customer name Customer surname Gender Tel.no email Country Order Brand HPK Model Model no Production location Year of release Price Sales PK ID FK Model FK Supplier ID Cost/unit Price/unit Qly sold Date sold Revenue Profit PK Order no FK Customer ID Customer name Customer surname Country OFK Model Quantity Unit price Date sold Total price Tracking no