What is the difference between IT Industry and Software Industry?
The software industry is responsible for the development of software utilizing the Software Development Life Cycle (SDLC). See (http://www.computerworld.com/s/article/71151/System_Development_Life_Cycle)for more information on that. The primary jobs are business analysts, developers, database analysts, and quality assurance engineers. Those roles play a vital role in the development and release of software.
The IT industry is broader, unlike the software industry which focuses on the programming and creation of software. The IT industry covers a wide range of tasks however the primary objective is to utilize computers in the act of managing and manipulating data.
The reality is there is no difference between these titles. Employers use them interchangeably. Theoretically, the difference is this: software engineers apply computer science and mathematical principles to design and develop software. Software developers simply develop software, i.e. carry out programming tasks.
Difference between senior software developer and software developer? According to me a software developer is the one who mostly interacts with the code ,writes debug and test it. Whereas A senior software developer is the one who creates architecture and manages or help software developers in case some issues are faced.