This lecture introduces the pipeline of modelling microcircuits, covering topics such as the diversity of neurons, synaptic and electrical diversity, microcircuit anatomy, and the biological reconstruction process. It explores the spatial scales of modelling, from meters to nanometers, and the levels of modelling, including neuron-based and molecular dynamics. The instructor discusses the data-driven algorithmic reconstruction process and the variation of laminar organization across the cortex, emphasizing the importance of understanding microcircuit connectivity and virtual tissue volumes for in silico experimentation.