What are parallel pathways?
There are three pathways within V1 that perform different functions in parallel.
Magnocellular pathway: begins with m type ganglion cells of the retina. These cells send axons to the magnocellular layers of the LGN. These layers project to layer IVCa of striate cortex, which in turn projects to layer IVB. Because of cortical neurons are direction selective this pathway may be involved in the analysis of object motion and the guidance of motor actions
The parvo-interblob pathway: originates with p-type ganglion cells f the retina, which project to the parvocellular layers of the LGN.The parvocellular LGN sends axons to layer IVCa of striate cortex which projects to layer II and III inter blob regions. Neurons in this pathway have small orientations-selective receptive fields, so perhaps they are involved in the analysis of fine object shape.
The Blob pathway: receives input from the subset of ganglion cells that are neither m or p type cells. These non m/p cells project to the koniocellular layers of the LGN. The koniocellular LGN projects directly to the cytochrome oxidase blobs in layers II and III. Many neurons in the blobs are color selective so they might be involved in analysis of color.

The term "parallel pathways" refers to the fact that there are multiple neural pathways in the brain that perform different functions, and that these pathways operate in parallel with each other. In the context of vision, the three main parallel pathways are the magnocellular pathway, the parvocellular pathway, and the Blob pathway. Each of these pathways originates in different cells in the retina and performs different functions in the visual system. For example, the magnocellular pathway is involved in motion detection and the guidance of motor actions, while the parvocellular pathway is involved in the analysis of fine object shapes. The Blob pathway is involved in color analysis. Together, these three pathways work in parallel to enable the brain to process visual information.