Time

• A tick is a measure of time in NetLogo models (like seconds or minutes). Ticks are used instead of seconds, minutes, or hours because ticks are standardized across all models and computers;
• In many NetLogo models, time passes in discrete steps, called “ticks”.
• Discrete time steps means, that the same code is repeated each tick. At each time step
  the agents evaluate their current state of fitness, sense the environment, take a decision
  and act. Each time step the model iterates through these processes.
• Calibration: Calibration refers to adjusting a model's parameters to match real-world data. While time itself might be calibrated to represent real-world units (e.g., 1 tick = 1 day), it's the division into discrete steps that defines the time progression.
• Event-based: Event-based models update based on specific events happening within the simulation, rather than following a fixed time schedule.

• Continuous: Continuous models update smoothly over time, with agents and the environment constantly changing. 

Discrete time steps mean that the simulation progresses in fixed intervals called ticks. In an wolf-sheep model, during each tick:

• Agents act: Wolves might hunt, sheep might graze and reproduce.
• Environment updates: Any changes to the environment, like resource depletion, might occur.