I quite often come across this question in my requirements engineering and business analysis workshops - Does SRS mean System Requirements Specifications or Software Requirements Specifications?
The answer is it can mean both and that's where the confusion begins. Fortunately for other kinds of requirements such as business requirements or functional requirements have distinct acronyms unlike above two types of requirements.
As I have drawn the image, the system is a broader concept than software.
Systems usually comprise of 4 key elements - People, Process, Technology, and Partners.
Technology, in turn, contains aspects such as Hardware, Software, and Network.
However, in many instances, the hardware and network may not be affected by the project and only software is affected.
For example, we may add a new feature to an existing software solution. It may so happen that we do not affect people, process or partners.
In this case, technology requirements equal software requirements and system requirements equal software requirements.
However, for larger changes, typically software requirements will be the subset of solution requirements.
A BA professional with 5 years of experience
Infrastructure and web Conferencing System requirements