# Fundamental Data Structures

+ information to be processed: *abstraction* of some part of the real
  world
+ computer has a selected set of *data* about the real world
+ this data is an abstraction:
  + certain properties/characteristics of the real world are ignored
    because they are considered peripheral to the problem
  + therefore represents a simplification of facts
+ problem solving: defining the set of characteristics relevant to the
  problem
+ the *choice of representation* may involve several levels of detail:
  consider deciding the position of an object.
  + polar v. cartesian coordinates (and selection of origin)
  + floating point v. integer representation of coordinates

## The concept of data type

+ in maths, we have different types: whole, integer, rational, etc...
+ principle: *every constant, variable, expression, or function is of
  a certain data type*
+ adherence to this means the compiler can check constructs for
  legality and compatibility
+ programming languages provide base data types, which can be extended
  by the programmer
+ *cardinality*: the number of distinct values belonging to some type
  *T*