What is a scalar
Scalars have only the concept of size, but no direction. Completeness can be expressed through a specific value.
For example: weight, temperature, length, mention, time, heat, etc. are all data scalar.
Relationship of scalar, vector, matrix, tensor
These 4 concepts are constantly rising in dimensionality. It is easier to understand the metaphorical explanation with the concept of point-line polyhedron:
Interested parties can learn more about the following: