Software are part of our lives, they are into every fiber of our society. Whether its the communication, medical care, transportation, shopping, transactions or general maintenance, software are everywhere. Take for example the banking these days. We can access our bank accounts online on our laptop or tablet or cellphone using software. The bank tellers and employees can manage everything on computers using software, including interest calculation, record of daily transactions, customer requests, etc. Another example is shopping. We can buy everything online, without stepping out of our homes. We can select any item, pay online, get it delivered and return or cancel it- all using software.
But apart from positive impacts, there are certain negative aspects of software as well. Foremost among them is the software that can interfere with normal operation of our computers or network. Such malicious software can not only steal our data, they can also hack the network and spread any rumors. Similar is the scenario with use of encryption software to exchange coded data. This can be a beneficial thing in business and a harmful activity if certain people use it for nefarious means (terrorist activities, etc.)
Software engineering plays a key role in software project development. It is essential to understand the needs of the client (requirement analysis & management) and changing the scope of the project and assimilating the change in design (change management). These are all important components of software engineering.
Hope this helps.