Quantum measurement and entanglement are distinct concepts in quantum physics, although they are closely related.
Entanglement is a phenomenon in which two or more quantum systems become correlated in such a way that the state of one system cannot be described independently of the other(s). This correlation persists even when the entangled systems are spatially separated. Entanglement is a fundamental feature of quantum mechanics and has been experimentally observed and utilized in various applications, including quantum communication and quantum computing.
Quantum measurement, on the other hand, refers to the process by which a quantum system's properties are determined or observed. When a measurement is performed on a quantum system, its state "collapses" into one of the possible measurement outcomes. The act of measurement is generally associated with extracting information about a specific observable of the system, such as its position, momentum, or spin.
While measurement and entanglement are distinct, they are interconnected. When an entangled system undergoes measurement, the measurement outcomes on one subsystem become correlated with the outcomes on the other subsystem(s). This correlation is often referred to as "spooky action at a distance" and was famously described by Albert Einstein, Boris Podolsky, and Nathan Rosen in their EPR (Einstein-Podolsky-Rosen) paradox paper.
In this sense, you can say that quantum measurement reveals or manifests the entanglement between quantum systems. Entanglement plays a crucial role in understanding the outcomes of measurements and the statistical correlations observed in quantum experiments.
However, it's important to note that not all quantum measurements involve entanglement. Measurements can also be performed on individual quantum systems without any entanglement present. Entanglement is a special type of correlation that arises from specific quantum states and interactions.
So, while entanglement and quantum measurement are connected, they are not identical. Entanglement is a property of quantum systems, whereas measurement is a process by which properties are observed or determined.