Think, you are going to build a high rise building on a land.
Now you need to consider the Requirements before you start, such as:
- Architecture or Design Engineer
- Soil Test Engineer
- Wind Pressure Test Team
- Man Power
- Water Supply
- Workers living/rest area
- Enough Fund
- Project Management
- Quality Management
- Security and Safety Control
Now the above contents are part of Requirements to build a high rise building.
From the above team, you get the technical outcome, which they hold as part of profession.
This is exactly, what is happening in software industry, a group of professional people involved to provide knowledge to build the technical specification, such as someone works on UI design, OO design, database design, graphic design, test case design, coding, integration, deployment team etc.
The above para will be part of handbook, that you can call Technical Specification.