What are the Database Objects in SQL???

Answer 1

Depends on the RDBMS

Typical ones are
Tables
Views
Triggers
Procedures
Macros
Functions

But you won't see all.of them in all RDBMS, or they may be named differently

Answer 2

Constraints
Database links
Triggers
Indexes
Views
Packages
Sequences
Functions
Procedures
Synonyms
Tables
Views

These are database objects specific to schema and there are nonschema database as follows:

Contexts
Directories
Parameter files (PFILEs)
Server Parameter files (SPFILEs)
Profiles
Roles
Rollback segments
Tablespaces
Users