What's in a name? Some sociologists study language and the symbolic meaning we collectively understand from our words. It is notable that it is virtually impossible to completely describe anything and that communication generally consists of expressions of the most significant parts of the thing or idea.
Depending on where you receive your news from, immigrants who come to the United States without legal authorization are commonly referred to as either "illegal immigrants" or "undocumented workers". So much is communicated with these two very different descriptions of the very same people.
One labels a human being as "illegal" as if the very fact of their existence violate laws... not to mention "alien" as if they came from some other galaxy rather than the lower part of the very same North American continent we reside in.
The term "undocumented worker" acknowledges the reason for their presence in the country (work), and that their papers are just not in order. (Ever notice that pets and immigrants both need paperwork registered with government agencies? I have an undocumented basset hound who refuses to do any work.)
The term "undocumented worker" doesn't tell us about what their intentions are... Will they file paperwork? Do they want to be citizens? Is their presence here a last desperate act to provide for their family? Are they here just to take advantage of the generosity of the American tax payer?
Really, do I need all that information anyhow? Maybe I do, but really the whole topic gets somewhat confusing when I try to determine where I stand on an issue based on the ideals I was raised with. My grandmother taught me that it was rude to quiz guests about the purpose of their visit when they arrive unannounced. And my Dad taught me that it's important to find out who is at the door before I open it.