The reactor antineutrino anomaly refers to a consistent deviation from unity in the observed-to-predicted event rate ratios in reactor neutrino experiments. This anomaly, observed at a 98.6% confidence level, is attributed to a 3% increase in the predicted antineutrino flux, leading to a 5.7% average deficit in event rates. The anomaly is consistent with a possible energy-independent suppression of the antineutrino flux at distances greater than 15 meters, suggesting the existence of a fourth non-standard neutrino state. The analysis of reactor data, gallium solar neutrino calibration experiments, and MiniBooNE-ν data disfavors the no-oscillation hypothesis at 99.8% confidence level. Oscillation parameters indicate that the new neutrino mass squared difference is greater than 1.5 eV² (95%) and the mixing angle squared is 0.14 ± 0.08 (95%). The results also revise constraints on the θ₁₃ mixing angle. The anomaly is discussed in the context of a fourth neutrino state, with the possibility of a correlated experimental artifact or an error in the antineutrino flux prediction. The analysis of reactor data, including the Bugey-4, ILL, and other experiments, confirms the anomaly, with the observed event rate ratios deviating significantly from the expected values. The anomaly is consistent with a fourth neutrino state, with the required mass squared difference and mixing angle. The results are compared with other experiments, including Gallex, Sage, and MiniBooNE, to assess the compatibility of the anomaly with other short baseline neutrino experiments. The analysis highlights the importance of accurate antineutrino flux predictions and the need for further experimental studies to clarify the anomaly.The reactor antineutrino anomaly refers to a consistent deviation from unity in the observed-to-predicted event rate ratios in reactor neutrino experiments. This anomaly, observed at a 98.6% confidence level, is attributed to a 3% increase in the predicted antineutrino flux, leading to a 5.7% average deficit in event rates. The anomaly is consistent with a possible energy-independent suppression of the antineutrino flux at distances greater than 15 meters, suggesting the existence of a fourth non-standard neutrino state. The analysis of reactor data, gallium solar neutrino calibration experiments, and MiniBooNE-ν data disfavors the no-oscillation hypothesis at 99.8% confidence level. Oscillation parameters indicate that the new neutrino mass squared difference is greater than 1.5 eV² (95%) and the mixing angle squared is 0.14 ± 0.08 (95%). The results also revise constraints on the θ₁₃ mixing angle. The anomaly is discussed in the context of a fourth neutrino state, with the possibility of a correlated experimental artifact or an error in the antineutrino flux prediction. The analysis of reactor data, including the Bugey-4, ILL, and other experiments, confirms the anomaly, with the observed event rate ratios deviating significantly from the expected values. The anomaly is consistent with a fourth neutrino state, with the required mass squared difference and mixing angle. The results are compared with other experiments, including Gallex, Sage, and MiniBooNE, to assess the compatibility of the anomaly with other short baseline neutrino experiments. The analysis highlights the importance of accurate antineutrino flux predictions and the need for further experimental studies to clarify the anomaly.