What is a web sdr?

Answer 1

SDR stands for Software Defined Radio i.e., "radios that provide software control of a variety of modulation techniques, wide-band or narrow-band operation, communications security functions (such as hopping), and waveform requirements of current & evolving standards over a broad frequency range."

Simply put SDR is defined as :

"Radio in which some or all of the physical layer functions are software defined"

SDR defines a collection of HW and SW technologies where some or all of the radio's operating functions (also referred to as physical layer processing) are implemented through modifiable SW or firmware operating on programmable processing technologies

Now, coming to Web SDR, SDR is made available through web. Here, radios are available at one place and connected to the web so that by browsing to those sites through the relevant URLs, you can tune the stations virtually and listen to those stations. It is really funny and inspiring

Answer 2

A webSDR is a Software Defined Radio (i.e. characteristics configurable in software) which is accessible via a web interface. Normally the device can be used by many users simultaneously.