Devices is the record of equipment the business owns: laptops, phones, tablets, and the hardware that runs the office.
Each entry carries the make and model, its condition, what it cost, when it was bought, and whether it is in use or available.
Why record the purchase cost
Three reasons, and the third is the one people find useful later.
Your accounts. Equipment above a certain value is an asset rather than an expense, and it appears on your balance sheet. Your accountant needs the date and the amount.
Insurance. A claim goes much better with a list that predates the incident.
Replacement planning. Purchase dates turn "the laptops are getting slow" into a number you can plan around. Equipment fails in clusters, because it was bought in clusters, and knowing three machines are the same age turns a surprise into a budget line.
In use versus available
Worth keeping current in a business with field staff, where the same phone or tablet moves between people.
The value is not asset control so much as knowing what you already have before buying another one, which is a mistake most growing businesses make at least once.
Alongside the rest
Equipment here, subscriptions in Software and Apps, and who can get into which system in team access. Together they answer what the business runs on, which is the question nobody can answer from memory.