The study of entanglement in particle physics has gained significant momentum in recent years, with researchers exploring its potential to detect entanglement and test Bell inequalities at colliders. This review, covering developments up to the beginning of 2024, presents the definitions, tools, and basic results necessary for understanding these advancements. It summarizes key findings from experimental data in B meson decays and top-quark pair production, focusing on both qubit and qutrit systems (spin 1/2 and spin 1 particles, respectively). The review also discusses how entanglement can be used to probe new particles and fields beyond the Standard Model. The authors highlight the importance of quantum state tomography in characterizing the full quantum state of systems after interactions, which is crucial for detecting entanglement. They also address the violation of Bell inequalities, which implies nonlocal correlations and challenges classical physics. The review covers various processes, including top-quark pair production, τ-lepton pair production, and Higgs boson decays, and discusses the use of entanglement to test for new physics.The study of entanglement in particle physics has gained significant momentum in recent years, with researchers exploring its potential to detect entanglement and test Bell inequalities at colliders. This review, covering developments up to the beginning of 2024, presents the definitions, tools, and basic results necessary for understanding these advancements. It summarizes key findings from experimental data in B meson decays and top-quark pair production, focusing on both qubit and qutrit systems (spin 1/2 and spin 1 particles, respectively). The review also discusses how entanglement can be used to probe new particles and fields beyond the Standard Model. The authors highlight the importance of quantum state tomography in characterizing the full quantum state of systems after interactions, which is crucial for detecting entanglement. They also address the violation of Bell inequalities, which implies nonlocal correlations and challenges classical physics. The review covers various processes, including top-quark pair production, τ-lepton pair production, and Higgs boson decays, and discusses the use of entanglement to test for new physics.