DBMS is an acronym for Database Management System. A Data Warehouse in DBMS is a relational database designed for analysis and query instead of transaction processing. It generally consists of historical data that is extracted from transactional databases and other data sources. It helps in separating the transactional workload from the analysis workload. Further, it allows the organization to combine data from numerous sources.
Along with a relational database, the environment of a data warehouse also consists of an Online Analytical Processing (OLAP) engine, extraction, transformation, and loading (ETL) solution, and various client analysis tools that help in managing the data gathering and delivering processes.
To get an insight into data warehousing, you must check out Data Warehouse Tutorial.
You should also register for an industry-recognized Data Warehousing Training to become a professional in this field.
Also, watch this YouTube video tutorial about Data Warehousing: