The difference between "customized" and "custom"
Hi all,

I know the difference might be delicate and hard to describe. Here is how I understand it as a non-native English speaker: "custom" refers to the nature of an object which is made or done for a particular group of customers; "customized", however, is not as broad and only means something being modified or changed according to the customer's needs. Is it the exact difference between these two words? Also I'm not so sure about their different uses. Help much appreciated !

Question

The difference between "customized" and "custom"
Hi all,

I know the difference might be delicate and hard to describe. Here is how I understand it as a non-native English speaker: "custom" refers to the nature of an object which is made or done for a particular group of customers; "customized", however, is not as broad and only means something being modified or changed according to the customer's needs. Is it the exact difference between these two words? Also I'm not so sure about their different uses. Help much appreciated !

Answer

Rico, in American English your description was perfect.  Although "Custom" and "Customized" can be used interchangeably as adjectives, most American English speakers would not use the adjective form of the word "customized".  They would differentiate by using "custom" as an adjective and "customized" would be used in its verb form.  
Here are a few examples to further illustrate how I, as an American English speaker would differentiate the two words.
"I make custom cabinets." - "custom" refers to the nature of the cabinets which can be made in any size, as opposed to stock cabinets, which are available in pre-defined sizes. (Applies to a broad audience - as Rico described)
"I make customized cabinets." Although it has the same meaning as the first sentence and it would not be improper, for most Americans, the second sentence would sound wrong.
"I have customized the cabinets to fit your kitchen." - "customized" as a verb (applies to a specific group, the homeowners, as Rico described).

Answer

Hi Rico, 'Custom' and 'Customized' both mean the same thing in the context you are talking about. You can have your car customized, or you can buy a custom built car, the definitions are the same, the only thing I would say is to be careful about you American & British spellings. We Brits do not use the Z, preferring to use a S instead.

Answer

Hey Rico,

I hope this helps you.

custom (noun): the usual way of acting/being (It is a custom for brides to wear white 
wedding dresses)
customs (noun): taxes or fees paid to a country/ government when products/goods 
come into or out of a country (I went through customs at the airport without
any problems)

custom/ customized (adjectives): made/ changed specially for individual customers/needs/taste etc (I bought a custom/ customized kitchen)

So in the adjective forms, you can use both in the same way. In England we use customized as the adjective (a customized website), whereas in the US I believe custom as an adjective is used more (a custom website). The verb however is always to customize, in both countries (not to custom).

Let me know if you have any questions!