Procurement is the whole series of activities resulting in acquisition of goods and services, as per requirement.
Tendering is one formal method through which buyers and sellers are linked together for a possible business relationship.
The buyer puts together compete detail of the requirement including all specifications, terms and conditions in one set of documents known as Tender enquiry documents and issues the same to prospective bidders, for inviting bids.
Procurement may take place with or without entering into tendering process, dpending upon discretion of the buyer.