Get all needed definitions for f, which depends on the function g:

FullDefinition recursively prints the definitions of unprotected symbols appearing in the definition of a symbol:

Note that the definition of h is included, but not the definition of the protected symbol g:

For a symbol whose definition does not depend on others, FullDefinition is generally equivalent to Definition:

For read-protected symbols, definitions are not given:

FullDefinition gives attributes, defaults, options, messages and values:

FullDefintion[pattern] gives recursive definitions for the symbols returned by Names[pattern]:

Save writes the output of FullDefinition to a file:

Definition does not give messages:

FullDefinition does give messages:

Use Messages to get the messages:

FullDefinition has the attribute HoldAll:

This gives the definition of symbol itself:

This gives the definition of its value:

FullDefinition is an output form; it does not evaluate:

By default, definitions attached to "System`" symbols are not pulled in:

Use ExcludedContexts{} to pull in definitions from all contexts:

Alternatively, attach definitions to your own symbols:

FullDefinition["symbol"] gives no values if there is no symbol named "symbol":

FullDefinition["symbol"] also gives no values if symbol has no values:

When using a pattern without a context mark, all definitions for matching symbols on $ContextPath are given:

Use a pattern with an explicit context mark to avoid potentially matching symbols from system or other contexts: