PHP Quotes

PHP-Quotes

Quotes indicate text (or information that is treated as text)

Referred to as text string

Single quotes:

echo $a; // results in the value of $a being printed

echo '$a'; // results in the word $a bring printed

To specify a literal single quote, put a backslash in front of it

echo 'Who said: "I \'ll be back"?';

// Who said: " I'll be back"?

Strings are surrounded by either single or double quotes. If you use double quotes, you can put a variable in a string and the results of echoing or printing that strings will include the value of the variable.
To specify a literal single quote, you will need to escape it with a backslash (\), like in many other languages. If a backslash needs to occur before a single quote or at the end of the string , you need to double it.
The results of echoing or printing that string will include the value of the variable:

echo "$a"; // results in the value of $a bring printed.
$link = "<a href='http://mycompany.com'>Example</a>";  
This called "Variable interpolation".