What is the difference between internal table and Database table ?

Intenral table is a local table which will be available at runtime only where as database table will hold the data and it is stored permanently.

Internal tables are used for temperoray storage of data during Runtime . 

Data base tables save data permanently . 

DATABASE TABLE: It is a physically existing permanent container in database, which maintains data in terms of rowa and column.

INTERNAL TABLE: It provides a means of taking data from database table and storing it in working memory in ABAP.

Database table is permanent while internal table is temporary.

database table have master and transaction data while internal table does not have any master and transaction data.

database table have it's own memory.

Database tables are at the database level, and has permanent memory. But whereas Internal tables are created dynamically and executed only during runtime. Internal tables doesnt have permanent memory and gets terminated with the termination of program.

Both Internal Table and Database table hold data. 

-> Internal Table data is available in ABAP Memory, Database data is stored in SAP Memory

->Data in internal table is available for use only in time of execution , Database tables hold permanent Data.

-> Database queries can me used on both Internal table and Database table