One of my (many) hats, believe it or not, is HR Specialist for the Federal government. All of the posts above gave good answers, but I'd like to add that the biggest difference between "junior" and "senior" in HR speak is not what you can do, but rather what you are paid to do.

Most work projects can be divided into three kinds of work: easy, moderately complex, and very complex. In terms of the amount of work in each category there's a little work in the easy category (someone has to do the photocopying, for example) and some of the work is in the "very complex" category, but the majority of the work usually falls in the middle ground. Given this scenario the most cost-efficient way to do business is to hire a few, skilled, highly paid individuals to do the "very complex" stuff; a few unskilled, low paid individuals doing the "easy" stuff; and everyone else stuck in the middle. This way you don't have to pay for skills that you don't need, and you keep your salary costs down.

Now this doesn't say anything about what all those shmucks (the "junior" types) doing the "moderate" work are actually capable of doing. They might all be freakin' geniuses with 200 IQ's... but a company could care less. They only need (for example) a couple of skilled folks in the high skilled jobs, and so long as everyone else does what they're supposed to, all is well.

Now, just because a company isn't willing to pay a highly skilled person in a moderately skilled job a high amount of money doesn't mean that company won't take advantage of the situation if it presents itself. Smart people are good to have in a company... they take initiative, they go beyond their job description, they add to the company in lots of ways. Companies love these employees, because they're getting unexpected perks from these guys without having to pay for it. In this respect Merlyn's joke wasn't really a joke at all: "A junior programmer is just a programmer who expects less pay, because they don't have the budget for a real programmer." But I would add, if the SuperGenius Junior programmer leaves, they're easier to replace because although a company would love to pay a SuperGenius Junior-level pay, they really don't need a SuperGenius so they can live without it if they have to.

The big downside here is that it is entirely possible for a SuperGenius Junior to work for a less-talented, less-skilled, (but higher paid) superior. Again, from a company's perspective this is generally ok, so long as the senior employee does the work the company expects, and the junior employee does what he is expected to do. Now, if the company was smart, they'd find a way to boot the senior and replace him with the junior, but this doesn't always work out that way for lots of different reasons (seniority, commitment to employees, non-programming skills, etc. all play into this kind of decision.)

Gary Blackburn
Trained Killer