Catalog vs Directory vs Inventory vs Register

When to use each in English, with meaning, register, and examples.

Catalog

Top 2,000 (common)B1

Directory

Top 2,000 (common)C1noun

Inventory

Top 5,000 (fairly common)B1noun

Register

Top 2,000 (common)B2verb
 CatalogDirectoryInventoryRegister
Pronunciation🇬🇧 //ˈkæt.əl.ɒɡ//🇺🇸 //ˈkæt.əl.ɒg//🇬🇧 /["/dəˈrektəri//daɪˈrektəri/"]/🇺🇸 /["/dəˈrektəri//daɪˈrektəri/"]/🇬🇧 /["/ˈɪnvəntri/"]/🇺🇸 /["/ˈɪnvəntɔːri/"]/🇬🇧 /["/ˈredʒɪstə(r)/","/ˈredʒɪstəz/","/ˈredʒɪstəd/","/ˈredʒɪstərɪŋ/"]/🇺🇸 /["/ˈredʒɪstər/","/ˈredʒɪstərz/","/ˈredʒɪstərd/","/ˈredʒɪstərɪŋ/"]/
MeaningA list of items, usually in a book or online.A list or collection of information about things, like names, addresses, or files.A list of items that a person or business has.A way of speaking or writing that fits a situation.
ExampleThe library has a new catalog of available books.The directory on the computer contains all the files related to the project.The store's inventory includes over 1,000 different products.You need to register for the conference in advance to secure your spot.
RegisterNeutralNeutralNeutralNeutral
How commonTop 2,000 (common)Top 2,000 (common)Top 5,000 (fairly common)Top 2,000 (common)
CEFR levelB1C1B1B2
Part of speechnounnounverb
Collocationsonline catalog, product catalog, library catalog, catalog entry, catalog itembusiness, telephone, trade, check, consult, compile, in a/​the directory, directory of, business, telephone, trade, check, consult, compile, in a/​the directory, directory ofcomplete, comprehensive, detailed, compile, complete, conduct, list something, in an/​the inventory, on an/​the inventory, excess, surplus, unsold, stock, replenish, liquidate, control, managementformally, officially, properly, be required to, have to, must, as, at, for, newly registered, barely, hardly, dimly, fail to, not seem to, begin to
Antonymsdisarray, chaos, randomnessfile, documentdepletion, lack, shortagecolloquial, informal
Common mistakesConfusing with 'catalogue' which is the British spelling., Using 'catalog' as a verb incorrectly, instead of the noun form., Mistaking it for 'inventory' which can imply a detailed list of stock.Mixing it up with 'directory' vs 'directly'., Using 'direct' instead of 'directory' when referring to a list., Confusing the spelling with 'directrey'.Confused with 'invent' or 'invention'., Using it as a verb incorrectly., Saying 'inventories' when referring to a single list.Confused with 'registrar', which is a person who keeps records., Using 'register' to mean 'register for an event', which is different., Misunderstanding the term as only relating to written language, ignoring spoken forms.
Usage notesUsed when referring to organized lists of items, products, or works. Avoid in very casual conversations.Used in contexts like business, computers, and phone listings. It is appropriate when talking about organization systems but may sound overly formal in casual conversations.Commonly used in business contexts to discuss supplies or stock. Not usually used in casual conversation.Use 'register' when discussing levels of formality in language. Appropriate in both academic and casual discussions. Avoid using it in purely informal or slang contexts.

Frequently asked questions: Catalog vs Directory vs Inventory vs Register

What's the difference between Catalog, Directory, Inventory, and Register?

Catalog: A list of items, usually in a book or online. Directory: A list or collection of information about things, like names, addresses, or files. Inventory: A list of items that a person or business has. Register: A way of speaking or writing that fits a situation.

Which is more advanced: Catalog, Directory, Inventory, and Register?

Directory is the highest level, at C1, on the CEFR scale.

Are Catalog, Directory, Inventory, and Register the same CEFR level?

Catalog: B1, Directory: C1, Inventory: B1, Register: B2 on the CEFR scale.

Can you show an example of each?

Catalog: The library has a new catalog of available books. Directory: The directory on the computer contains all the files related to the project. Inventory: The store's inventory includes over 1,000 different products. Register: You need to register for the conference in advance to secure your spot.

Can I use Catalog, Directory, Inventory, and Register interchangeably?

Not always. Catalog, Directory, Inventory, and Register are related and overlap in some contexts, but they differ in register, how common they are, and usage, so swapping one for another can change the meaning or tone. Check the differences above before substituting.