Guard duty is managed threat detection service continuously monitored your workloads, accounts,data for malicious activity
Database management system is a software that enable users and application manage, retrieve and manipulate in database
Webserver is software http request from client they return http response such as webpage ,file ,data,html and json
Database server : store , retrieve,manage and update the data over network act as a central management
Asynchronous replication is method of AWS copying data from source database to one or more secondary database (replica)