Hardware is the physical equipment that you need to fulfil a requirement. It may be a standard part, off the shelf or it may be a custom design. For example, a microcontroller coupled with a fluid level sensor and internet connector would make the custom hardware for a remote fluid level monitoring system, transferring it's measurements to a central database allowing a secure web application to review and control a national distribution of sensors.
Field Programmable Gate Arrays (FPGA) blur the line between hardware and software by enabling a custom hardware implementation to be designed and described by a software language such as AHDL or VHDL. Larger devices can even implement embedded processors alongside other custom functions.
Here are some examples of the type of hardware engineering that we can help you with