Learn English – Difference between “ad hoc” and “impromptu”

I will disagree with Robusto and Mr. Disappointment insomuch that the two words have very different meanings. This is copied from my local dictionary and I think it describes the difference well:

While prototype and archetype are often used interchangeably, they really mean quite different things. An archetype is a perfect and unchanging form that existing things or people can approach but never duplicate (: the archetype of a mother), while a prototype is an early, usually unrefined version of something that later versions reflect but may depart from (: a prototype for a hydrogen-fueled car).

In other words, a prototype is a (usually physical) draft. An archetype is an ideal example or theoretical perfect form. Something could correctly be labeled both a prototype and archetype but generally prototypes are inferior to the final product. Their very label of prototype implies that it will be replaced with a different form later in the design process.

The final prototype can be considered the primary modeling example if the object is intended for mass production and a loose usage of "archetype" could apply. Then the meaning would shift from focusing on the prototype and, instead, focusing on the reproductions. As in, the reproductions better faithfully mimic the archetype because if they didn't than the process is flawed. This usage holds no implications about the perfection of the archetype and, therefore, I consider prototype the appropriate word.

Even the other dictionary examples posted in the other examples are not suggesting they are synonyms:

prototype - a first or primitive form

archetype - original pattern from which copies are made

"First form" and "original pattern" are similar but their usages are drastically different.

archetype - an original model or type after which other similar things are patterned; a prototype

Using "prototype" to describe "archetype" works but the usage example helps reveals the difference:

"'Frankenstein' ... 'Dracula' ... 'Dr. Jekyll and Mr. Hyde' ... the archetypes that have influenced all subsequent horror stories" (New York Times).

"Prototype" would be incorrect in that sentence. Here is the same dictionary's definition of prototype:

prototype - an original type, form, or instance serving as a basis or standard for later stages.

The difference in meaning is again hard to see but prototype is a staged type or form: It is "original" in the sense that it came before the next one in sequence. "Archetype" is "original" in the sense that there wasn't anything else before it. You can (and usually do) have a sequence of prototypes; you generally only have one archetype.

There is substantial overlap in meaning, and if you use one where the other would've been more appropriate, native speakers will still understand what you meant; so don't worry about it too much.

For your purposes, I think the most important distinction is that row can only be used to refer to an arrangement of discrete items. For instance, in the sentence "He drew a line between the two points on the map", line cannot be replaced by row.

I can't presently think of an example where I'd say you can't go the other way -- replacing row with line -- but there certainly are cases where it would be odd. For instance, we normally always speak of a table of numbers having rows (which are always horizontal) and columns (which are always vertical). If you referred to a line of a table, that would be peculiar, but not wrong, and I think would be understood as unambiguously horizontal (by analogy with lines of text on a page, which are always horizontal ... well, as long as you're not talking about one of the East Asian languages that can be written vertically, anyway).