What are the best terms to describe web development services?

If I’ve understood you right, when you say back-end, I’d include terms like:
Foundation
Structure
Architecture
Framework
Functionality

I’d say Engine. I do a bit of development using Wordpress as a CMS and I call it the Engine, as people can more easily grasp the idea of complex workings ‘under the hood’ of their blog or site by using a term they’re already familiar with.

Or you could keep it simple and just say : We build websites. If the client asks more, then add how you do the back-end development of websites

From the marketing and sales perspective, the reason you get blank stares is that the decisionmakers are not technical. Therefore, your marketing materials need to be addressed to the audience. I suspect the “start-ups and entrepreneurs” you indicate you are usually dealing with would be the CEO or owner. If you go with Mirza’s suggested approach, you could incorporate several of the other terms mentioned in answers here. Terms that have buzz value, but are not too technical.

The idea is that the audience is focused on the value proposition the Web site expenditure will ultimately provide to his or her business.

For example: At WebWorld, we build great Web sites. From site architecture through user interface design to back-end engines robust enough to handle all your transaction needs, we work with you to produce a site that looks good and performs efficiently to keep your customers coming back.

Interestingly, the category choices you made are also good buzz words these days: Web 2.0 and Web development.

If you want input on specific text or a specific use for the description you are asking about, send me a comment or email. I would be happy to look something over and give you feedback.

What about coming up with a few creative yet layman-friendly analogies? I like the “under the hood” example, or maybe like the machinery behind a clock

I’m with mizra 100% – so many web development shops toss around the same boring old jargon. Most of them probably wouldn’t know what architecting or frameworks really are but they throw it up on their laundry list anyway. Keep it simple: if your target is people who don’t grok “back-end development” or think it has something to do with gluteus exercises then don’t make it more complex.

Let me preface this answer by stating that I am an entrepreneur 2.0, and I know just enough about web design and development to cause trouble.

I assume that the people giving you blank stares probably need to hear more of the benefits than the particular component services that you offer.

If you can claim this about yourselves, I like the sound of these:
– We make bulletproof websites that work the right way.
– If a website was a car, we build the engine and fill it with gas.
– We use the right technology to build rock-solid websites.
– We create fast, strong, accurate websites.

Good luck.