SQL Server timestamps are a crucial component of relational databases, allowing for efficient storage and retrieval of data that changes frequently. They provide an accurate way to track changes to data over time, helping to prevent concurrency issues and ensure data integrity. Timestamps can be used to store dates and times with precision, and their format is typically YYYY-MM-DD HH:MM:SS.NNN. In a .NET application, SQL Server timestamps can be used to create a timestamp column in a database table, such as the `FirstCreatedTime` and `LastUpdatedTime` columns in the `UserProfiles` table. By using timestamps, developers can track changes to data over time, provide an audit trail of data changes, and improve performance by tracking when data was last accessed. Additionally, timestamps can be used to understand how data changes over time, making them a valuable tool for applications that rely heavily on timestamped data.