This document discusses key concepts in computer programming languages including code editors, translators, high and low level languages, comments, input/output functions, constants, variables, and data types. It explains that code editors are for writing code, translators convert between high and low level languages, comments start with /* and end with */, and variables can change value during program execution unlike constants.

2. Key concepts:
 Code Editor-Meant for editing the
actual code.
 Translator- Meant for translating the
high level language to low level language
& viceversa. Two types of translators are
compilers and Interpreters.

3. Two types of Computer languages:
* High level language-Made up of
common English’
example: C,C++,Java etc.,
*Low level Language: Also known as
machine
language. Made up binary
numbers.ie., 0’s and 1’s

4. Comment line:
* Starts with /* and ends with */.
* The compiler ignores this line as
it is just meant for the user or
others to understand what is being
done in a particular portion of the
program.
* Does not get diplayed on the
output screen.

5. Printf()-Output function.It
is meant for displaying the
content on the output
page.
Scanf( )-Input function.It is
meant for accepting the
user’s input during the
program execution.

6. Constants
As the name implies, the value stays fixed.
It doesn’t keep changing during the time of
execution unless and until the user makes a
change.
The two types of constants are Numeric
constants and character constants.

7. Variable
As the name itself implies , the value of the
variable keeps changing during the time of
program execution.
How to declare a variable?
The syntax to declare a variable is,
datatype variablename;
Example:
Int Num;
Here int refers to interger datatype and Num
refers to the name of the variable.

8. Datatypes
The data type refers to the type of
the data used in the program. There
are four basic types. They are int,
float, char and double.