Markov models describe systems in which the future state depends only on the current state, not on past states. This memoryless property makes them tractable for various sequential tasks.

Example: A board game where only the current position matters for the next move. They are used for forecasting, stock market analysis, and other time-dependent phenomena.

Hidden Markov Models (HMMs) model sequential data with a series of hidden states that produce observable outputs. They solve evaluation, decoding, and learning problems for sequences.

Key concept: HMMs have a hidden state process (which follows the Markov property) and an observation process dependent on the current state. Example: Inferring the weather in a windowless room by observing people’s clothing.

Markov chains model sequences where only the current state determines the next state. Over time, they often settle into a stationary distribution that reflects long-term probabilities.

Everyday example: Weather patterns where if today is sunny, there is an 80% chance tomorrow will also be sunny. Applications include stock market predictions and website navigation analysis.