We can get a partial result by only considering our vector layers, and running some vector analysis tools on them. There are different methods for different type of analysis; however, we can group the most frequently used methods into the following four groups:

• Overlay analysis: Analyzing features according to their spatial relationships to other features. Common use cases are spatial queries and spatial joins.
• Proximity analysis: Analyzing the relationship of features based on some distances. The heart of this type in a traditional desktop GIS software is the buffer tool, while the rest of the work is basically overlay analysis.
• Neighborhood analysis: Analyzing (more often, statistically) neighbouring features of some input features. When we need to find the closest features to some input features, it is called a k-NN (k nearest neighbor) query.
• Network analysis: Analyzing a topological network, or some features on it. The most typical use case is to find the shortest path between two points on a road network.

Different GIS softwares are good at different analysis types. Although QGIS is a universal GIS, it offers a good coverage only in the most basic analysis types--overlay analysis and proximity analysis. PostGIS is exceptionally good in neighborhood analysis. As GRASS GIS forces the topological model on vector layers, it has the best capabilities in network analysis.