The Poincaré group is another name for the inhomogeneous Lorentz group (Weinberg 1972, p. 28) and corresponds to the group of inhomogeneous Lorentz transformations, also known as a Poincaré transformations.

Weinberg, S. Gravitation and Cosmology: Principles and Applications of the General Theory of Relativity. New York: Wiley, 1972.

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Weisstein, Eric W. "Poincaré Group." From MathWorld--A Wolfram Web Resource. http://mathworld.wolfram.com/PoincareGroup.html