ASIO Control Panel
'Audio Stream Input/Output' (ASIO) is a computer sound card driver protocol for digital audio specified by the Steinberg company. It provides a low-latency and high fidelity interface between a software application and a computer's sound card. Depending on your sound input device, you may get a better quality recording by using the ASIO driver, but if saving to MP3 format you probably won't notice the difference.
Different sound cards or USB devices often have an ASIO driver delivered with the device, and some universal ASIO drivers are available online. Each driver has a slightly different ASIO control panel. The control panel allows certain properties of the driver to be configured, such as the the "buffer size". The buffer size defines the number of samples per block, which affects the processing speed (latency). It has no effect on sound quality. Normally the default settings are OK.
Sometimes the sampling rate or sample bit depth can be selected, e.g. 96KHz, 24-bit etc. Higher values produce better quality recordings.