A distinction without a difference is a type of logical fallacy where an author or speaker attempts to describe a distinction between two things where no discernible difference exists. It is particularly used when a word or phrase has connotations associated with it that one party to an argument prefers to avoid.
Marty: "The last time Tap toured America, they were, uh, booked into 10,000-seat arenas, and 15,000-seat venues, and it seems that now, on their current tour they're being booked into 1,200-seat arenas, 1,500-seat arenas, and uh I was just wondering, does this mean uh...the popularity of the group is waning?"
Ian: "Oh, no, no, no, no, no, no...no, no, not at all. I, I, I just think that the... uh... their appeal is becoming more selective."