echo processes statements within single quotes and double quotes differently:

$name=Robot;
echo 'Hello, $name'; 
echo "Hello, $name";

The output will look like:

Hello, $name
Hello, Robot

So when you have a string in single quotes, it prints everything as it is (“literally”). When you put it in double quotes, it'll expand it, process it and then print it. Single quotes is faster; double quotes has far more uses.

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