The curse of dimensionality refers to the exponential growth of space as the number of dimensions increases, causing data points to become increasingly sparse.
As the number of dimensions increases, the chance of finding data points close to each other becomes nearly impossible unless the number of samples is very large.
Dimensionality reduction techniques like PCA, t-SNE, and autoencoders help simplify high-dimensional data by identifying and retaining the most informative features.
By reducing dimensions, these techniques mitigate the issues caused by data sparsity and improve computational efficiency, enabling better performance of machine learning algorithms.