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+# 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*
+