Dear student,

Software engineering is a detailed study of engineering for the design, development and maintenance of softwares. This professional field was introduced to address the issues of low-quality software projects.
It can be termed as a subpart branch of cse.
Software engineering is important because in almost every industry softwares are needed, in every business, and for every function.

You have to develop information systems by designing, developing, and installing software solutions using the knowledge of codings and advanced software techniques. You also have to determine.the operational feasibility by evaluating analysis, problem definition, requirements, solution development, and proposed solutions.

So, software engineering is the professional field of engineering which mainly focuses on to the development of software.