Simplify the following text for a Grade 12 native English-speaking person.
Original: Within the Hirundiniae , the name `` martin '' tends to be used for the squarer-tailed species , and the name `` swallow '' for the more fork-tailed species ; however , there is no scientific distinction between these two groups .
Simplified: Within the swallow , the name `` martin '' tends to be used for the squarer-tailed species , and the name `` swallow '' for the more fork-tailed species ; however , there is no scientific distinction between these two groups .