A system profiler is a program that can provide detailed information about the software installed and hardware attached to a computer. Typically workstations and personal computers have had system profilers as a common feature since the mid-1990s.
However, system profilers exist on most computing architectures in some form or other. System Monitor programs in mainframes essentially provide the same function as system profiler programs on personal computers.
Modern system profilers typically provide real time information on not only the CPU state (such as clock speed), GPU state, and attached hardware state (such as USB or FireWire devices).
System profilers came into use after punch cards were no longer needed to run programs. Mainframe computers had evolved into have modular architectures at the same time punch cards were being abandoned as input devices. Punch card based mainframe computer systems typically had very rigidly fixed architectures with little variation in input or output devices.
Since the 1990s hardware independent system profilers have emerged in some computing architectures, like Linux. Most Unix-like (aka POSIX compliant) operating systems have system hardware independent profilers.
In Apple Computer's classic Mac OS, this was done by an application called Apple System Profiler.
macOS' profiler is simply called System Information, and can be accessed via two methods. A GUI application, System Information.app, provides system information in simplified tables and trees, whereas detailed, highly-verbose information can be viewed upon executing the /usr/sbin/system_profiler binary in a terminal emulator.
In Microsoft Windows, similar information can be found by viewing the properties of "My Computer" or "This PC," pressing the Windows key and Pause/Break key simultaneously, or by executing the <!-- %windir%\System32\ -->[[msinfo32.exe]] binary.