What is Fabrication vs Welding?

Fabrication and welding are two somewhat related engineering technologies but with a few subtle differences.
Fabrication is a general term referring to the manufacturing process that entails design, material processing and part forming to the final assembly of the product. Manufacturing processes: Casting, forging, machining, welding, etc., and all the quality assurance and control activities related to these processes. Manufacturing is the process of converting materials into products of a particular design and functionality to address the market or consumer needs.
Welding also comes under the manufacturing process but is more sensitive and is basically used to join metal parts. It forms a great bond where there are metal materials by heat fusion or pressure fusion at the interface of the joining surfaces. Welding process refers to the use of heat to join metals and is a crucial technology in the manufacturing sector with application in automotive, aerospace, construction and ship building industries among others. Welding does not only involve joining two metallic components of the same type of material but also joining different metals, for example joining steel and aluminum.
Welding and fabrication are interrelated in terms of practical implementation of the fabrication methods with welding being one of the crucial essential steps of fabrication. For instance, manufacturing can use welding to join the two or more metal parts together to form a structure during manufacturing and at the same time use the same welding technique to repair the already manufactured damaged metal part. Thus, manufacturing and welding are interdependent, and both are the main driving force behind the manufacturing industry.