Nearline, Coldline, and Archive offer ultra low-cost, highly-durable, highly available archival storage. For data accessed less than once a year, Archive is a cost-effective storage option for long-term preservation of data. Coldline is also ideal for cold storage--data your business expects to touch less than once a quarter. For warmer storage, choose Nearline: data you expect to access less than once a month, but possibly multiple times throughout the year. All storage classes are available across all GCP regions and provide unparalleled sub-second access speeds with a consistent API.
https://cloud.google.com/storage/archival

https://cloud.google.com/spanner/docs/getting-started/set-up

The Real description is about Coldline storage Class:
Coldline Storage
Coldline Storage is a very-low-cost, highly durable storage service for storing infrequently accessed data. Coldline Storage is a better choice than Standard Storage or Nearline Storage in scenarios where slightly lower availability, a 90-day minimum storage duration, and higher costs for data access are acceptable trade-offs for lowered at-rest storage costs.
Coldline Storage is ideal for data you plan to read or modify at most once a quarter. Note, however, that for data being kept entirely for backup or archiving purposes, Archive Storage is more cost-effective, as it offers the lowest storage costs.
https://cloud.google.com/storage/docs/storage-classes#coldline

https://cloud.google.com/bigquery/docs/managing-jobs#view-job.
Cloud Debugger is for inspecting apps: https://cloud.google.com/debugger/docs.

When you create an instance using the gcloud command-line tool or the Google Cloud Console, you can specify which service account the instance uses when calling Google Cloud APIs.
https://cloud.google.com/compute/docs/access/service-
accounts#associating_a_service_account_to_an_instance