How can I find out more about the hardware inside my Mac?

While there’s the classic Apple menu -> About This Mac -> System Report, a terminal based alternative is the system_profiler command.

You can use a list of queryable types like so:

> system_profiler -listDataTypes
Available Datatypes:
SPParallelATADataType
SPUniversalAccessDataType
[...]

Once you’ve found one or more types, you’re interested in then just append it after the command like so: system_profiler <type1> <type2>

Let’s see how it looks in action:

> system_profiler SPPowerDataType
Power:

    Battery Information:

      Model Information:
          Manufacturer: DSY
          Device Name: bq20z451
          Pack Lot Code: 0
          PCB Lot Code: 0
          Firmware Version: 1002
          Hardware Revision: 1
          Cell Revision: 2400
      Charge Information:
          Fully Charged: No
          Charging: Yes
          Full Charge Capacity (mAh): 4569
          State of Charge (%): 74
      Health Information:
          Cycle Count: 81
          Condition: Normal

This is just an excerpt of what is otherwise a whole bunch of information.

Particularly interesting is the SPAirPortDataType which can be queried to see a list of SSIDs in the environment.