Vector data is not made up of a grid of pixels. Instead, vector graphics are comprised of vertices and paths.
The three basic symbol types for vector data are points, lines and polygons (areas).
Vector points are simply XY coordinates. When features are too small to be represented as polygons, points are used.
Vector lines connect vertices with paths. If you were to connect the dots in a particular order, you would end up with a vector line feature.
When a set of vertices are joined in a particular order and closed, they becomes a vector polygon feature. In order to create a polygon, the first and last coordinate pair are the same and all other pairs must be unique.
The Vector Processing menu contains several processing algorithms applied to vector data.