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Simply, whats the fundamental difference between $param and ${param} ?

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up vote 3 down vote accepted

There is none. It's for echoing a variable immediately followed by a string.

For example, if you have $param, but you want to have right after it, "lbs"

echo "${param}lbs"

Where as

echo "$paramlbs"

Would look for an incorrect variable name

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Correct, but not just for echo, but any time you do that kind of concatenation. – Dennis Williamson Dec 8 '09 at 6:36

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