Multicollinearity occurs in regression when variables are correlated, affecting model stability and interpretability.Variance Inflation Factor (VIF) measures how correlation with other predictors impacts variance of a regression coefficient.High VIF indicates strong multicollinearity, negatively impacting regression coefficients and standard errors.VIF calculation involves the coefficient of determination of an independent variable against other variables.Interpreting VIF values: 1 (no multicollinearity), 1-5 (moderate), >5 (high, intervention required), >10 (serious, model instability).Ways to reduce VIF include removing correlated variables, using PCA, and applying regularization methods.Comparing VIF to other methods like correlation matrix and eigenvalue decomposition for multicollinearity detection.Python implementation: Calculate VIF using statsmodels and create correlation matrix with Seaborn.VIF is crucial for identifying multicollinearity, guiding actions like variable removal or principal component analysis.In Python, VIF calculation can be performed using statsmodels library and correlation matrix visualization with Seaborn.