Karam J.J’s Answer
Mechanical engineering is a diverse subject that derives its breadth from the need to design and manufacture everything from small individual parts and devices (e.g., microscale sensors and inkjet printer nozzles) to large systems (e.g., spacecraft and machine tools). The role of a mechanical engineer is to take a product from an idea to the marketplace. In order to accomplish this, you need to understand the forces and the thermal environment that a product, its parts, or its subsystems will encounter; to design them for functionality, aesthetics, and the ability to withstand the forces and the thermal environment they will be subjected to; and to determine the best way to manufacture them and ensure they will operate without failure. Perhaps the one skill that is the mechanical engineer’s exclusive domain is the ability to analyze and design objects and systems with motion
To put it simply, mechanical engineering deals with anything that moves, including the human body, a very complex machine. Mechanical engineers learn about materials, solid and fluid mechanics, thermodynamics, heat transfer, control, instrumentation, design, and manufacturing to understand mechanical systems. The American Society of Mechanical Engineers (ASME) currently lists 36 technical divisions, from advanced energy systems and aerospace engineering to solid-waste engineering and textile engineering
Vijendra Singh Thakur, Lean Six Sigma
Vijendra Singh’s Answer
Mechanical Engineering is the broadest of all engineering disciplines, encompassing areas such as energy, fluid mechanics, dynamics, combustion, vibration, design, manufacturing processes, systems modeling and simulation, mechatronics, robotics, mechanics of material, rapid prototyping and composites.
Mechanical engineers are employed in virtually every kind of industry.
To add to the great input on this thread, my favorite aspect of mechanical engineering as a career choice is that it crosses so many industries. This increases the chances that your job and your passion intersect to form a great career. When your job and passion intersect, your daily work is less of a "job" and more of a "joy"
Almost everything that you touch that has been manufactured in mass involves a mechanical engineer. This means as you study mechanical engineering, you can investigate your personal interests (cars, planes, space, medical, home furnishing, apparel, public utilities, toasters, etc) through internships and networking to find a great job in a field that you love.