Ravi Sir's Cards › AWS
'single' vs "double"
What is a VPC: your own private network inside one AWS Region, example ThreeTierVpc 10.0.0.0/16.
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What this card says
Quotes
'single'
Exact text, no expansion.
"double"
$var and $( ) expand.
Key points
Cannot hold a single quote.
Escape $ with backslash.
Example
echo '$HOME'
Use when
Fixed strings, regex.
Messages with variables.