I'm using SQL Server the very first time and that i observe that a column rentals are known as Is Identity.

What doeds this suggest?

Do you know the benefits of marking a column property as Is Identity = Yes ?

Thanks ahead of time.

It really means the column uses the Identity(increment, seed) function to supply values for any primary key (usually). It's also called "Autonumber". The 2nd line below is definitely an example:

CREATE TABLE Table (
TableID bigint IDENTITY(1,1) NOT NULL,
DateTimeStamp datetime NOT NULL DEFAULT (getdate()),
Data nvarchar(100) NOT NULL,
CONSTRAINT PK_Table PRIMARY KEY CLUSTERED 
(
    TableID ASC
)

It functions like a default value for that column that batches for every record. Note that you could will also get the worthiness placed from SCOPE_IDENTITY(). Don't use @@IDENTITY because it is depreciated and may return the incorrect increase the risk for situation of triggers or nested contexts.

Flag showing a name Column - can be used a car-increment column (suggested for just about any table)

it's many implications like getting the id from the last placed row inside a table using @@IDENTITY or SCOPE_IDENTITY() etc.

Try: Understanding Identity Columns

It's equal to MySQL's AUTO_INCREMENT property. Usually utilized on a principal key column

All options that come with SQL Server IDENTITY property of posts. Along with a handy procedure to watch all Identity posts. http://www.sqllion.com/2011/08/identity-in-sql/