Pat Brisbin gives one of the most approachable explanations of the Unix shell's
if statement that I've seen.
if [ "string" != "other string" ]; then # same as if test "string" != "other string"; then fi
Unfortunately, many users come across this usage first and assume the brackets are part of if itself. This can lead to some nonsensical statements.
I will always hold my nose every time I type
fi, but I've grown more fond of shell scripting the last few years.