Type system is a set of rules that assigns a property called type to the various constructs of a computer program, such as variables, expressions, functions or modules
Type Error
A type error is erroneous or undesirable program behavior caused by a discrepancy between differing data types for the program's constants, variables, and methods.
Type Safety
The extent to which a programming language discourages or prevents type errors
Strong Typing
A strongly typed language typically disallows implicit conversions between unrelated types
Weak Typing
A weakly typed language makes conversions between unrelated types implicitly
Static Type Checking
Static type checking is the process of verifying the type safety of a program based on analysis of source code.
Dynamic Type Checking
Dynamic type checking is the process of verifying the type safety of a program at run-time
Manifest Typing
Manifest typing is explicit identification by developer of the type of each variable being declared
Type Inference
Automatic detection of type based on usage.
Duck Typing
If it walks like a duck and it quacks like a duck, then it must be a duck
