Classification of company assets

Along with greeting you, I would like to please if you could help me with a question I have. I am classifying the assets of the company and in the case of computers and laptops, for example, do I have to enter into the classification all those that exist in the organization or only one?

I remain attentive to your response, greetings and thanks

By your question, I'm assuming you are talking about filling in the asset register.
 
Considering that, you need to include in the asset register all assets that are related to the ISMS scope (in case the scope covers all organizations, then you need to consider all computers and laptops). But you do not need to include every single asset. You can create a single asset named "laptop" or, in case you need to use different classification levels, you can identify assets like "common laptop" and "development laptop", and define a different classification for each one.
 
This article will provide you a further explanation about the asset register:  

• How to handle Asset register (Asset inventory) according to ISO 27001 https://advisera.com/27001academy/knowledgebase/how-to-handle-asset-register-asset-inventory-according-to-iso-27001/