What is defect management? How do you log a bug?

It is to manage the defect of the application and to resolve the bugs on a timely basis. The following information needs to be included.  We must give meaningful information and make necessary assessment on each defeat. 

• Defect ID
• Defect summary
• Defect description - simulate the defect steps to reproduce the same error. Log down all the expected and actual results plus all the other relevant information. The information here is critical as it allows developer to know the issue before fixing the bug(s).
• Severity - product manager/owner or user needs to access/risks and what level of impacts to the business.
• Priority - impact analysis must be carried out 
• Environment - testing or production environment?
• Assigned to
• Status
• Images - Error message 

Popular defect management tools 

• Excel file 
• SpriaTeam, 
• Jira
• Azure
• AWS

How to prioritize a bug?

It is very much depend on the severity of the bug. How it is impact on the business. How much resources are available. i.e money and developers' time

Source from: https://www.guru99.com/top-20-bug-tracking-tools.html