Approach to gear use varies, but most common is the use of external microphones. Beyond that the most significant division is recording with the microphones mounted to a stand or clamped to something.. or mounted to oneself.
There is a wide range of approaches, ranging from folks using the internal mics of handled recorders to folks running multichannel microphone arrays and complicated gear-chains.
It used to be more common to find recorders with digital inputs which were often used as 'bit storage devices' fed by external converters and preamps, but as the quality of Analog to Digital Converters (ADCs) and microphone preamplifiers built into recorders has improved over the years, more and more tapers have moved away from using outboard units dedicated to those specific functions. As a result, current high-quality rigs tend to be much smaller, lighter, less complex and more reliable than they tended to be a decade or two ago.
What never changes are the most important fundamentals: well behaved microphones placed in an optimal location and used in the most appropriate configuration for the situation.