There are many kinds of signal generators and analysers available, including:
Whatever the specific generator or analyser type you require for your workplace testing and development tasks, all signal generators are essentially designed to produce various electrical signals in the form of waves.
These waveforms are then used as direct stimuli for other items of test equipment, including radio hardware, logic boards, and other electronic/electroacoustic devices that can be fed with particular waveforms during testing or troubleshooting processes.