The CLI also contains an online help system to provide descriptions and syntax for each command via the Help and Apropos commands. 
Giving no argument to Help, it lists all operators, keywords, built-in functions, available in nuBASIC divided into four categories: commands, instructions, functions and operators.
Giving as argument a keyword, Help displays the help text for that keyword. 

For example, the command help open prints out a text describing the Print statement, as follows:

help print

Print [list of expressions][;]

Prints list of expressions to standard output
If list of expressions is omitted, a blank line is displayed
If list of expressions is included, the values of the expressions are displayed.
Expressions in the list may be numeric and/or string expressions, separated by commas or semicolons.
A question mark (?) may be used in place of the word Print when it is the first statement in the immediate-mode editing.

Literal strings in the list must be enclosed in double quotation marks.

Apropos is command to search help content. It is used to search all help data for the string specified. This is often useful if one knows the action that is desired, but does not remember the exact command.

The following example demonstrates the output of the Apropos command:

apropos file
exec        Loads and runs a program file
load        Loads a program file in memory
save        Saves current program to file
close       Terminates input/output to a file.
flush       Shall cause any unwritten data for that file number to be written to ...
fopen       Establishes input/output (I/O) to a file.
input#      Inputs data from file that will be placed into a list of variables.
open        Establishes input/output (I/O) to a file.
plotimage   Loads and draws a bitmap from file on the screen starting at coords x...
print#      Prints list of expressions to file (0-standard output)
read        Reads data from file that will be placed into a variable.
seek        Moves the file pointer to a specified location
write#      Prints list of expressions to file (0-standard output)
eof         Checks the end-of-file indicator.
erase       Deletes file from disk
ferror      Tests for an error on a file.
fsize       Returns the current size in bytes of the file
ftell       Returns the current value of the position indicator of the file
playsound   Plays a sound (wav) specified by the given file name