Step 1: Pressure Definition.
Pressure is defined as force per unit area.
\[P = \frac{F}{A}\]
Step 2: SI Units.
- Force (\(F\)) is measured in Newtons (N).
- Area (\(A\)) is measured in \(m^2\).
Therefore,
\[1 \, \text{Pa} = 1 \, \frac{\text{N}}{m^2}.\]
Step 3: Alternative Units.
- 1 atm = \(1.013 \times 10^5\) Pa.
- 1 torr = \(\tfrac{1}{760}\) atm.
Final Answer:
\[
\boxed{\text{pascal}}
\]