Main categories of SQL Server Data Types,
1.     
Numeric 
a.     
Exact
Numeric 
b.     
Approximate
Numeric 
2.     
Date and Time 
3.     
Character
String 
a.     
Non-Unicode
Character String 
b.     
Unicode
Character String 
4.     
Binary 
5.     
Others
The following detail
as given below,
| 
DATA TYPES | 
SYNTAX | 
DESC | 
| 
Integer             | 
INTEGER           | 
It is integer data type and used to specify an integer value. | 
| 
Smallint | 
SMALLINT | 
It is small lint data type and used to specify small integer value. | 
| 
Numeric | 
NUMERIC(X, Y) | 
It is numeric data type. Here X is a precision value and Y is scale   values. | 
| 
Real | 
REAL | 
It is a real integer and used to specify a single precision floating   point number. | 
| 
Decimal | 
DECIMAL(X, Y) | 
It is decimal data type. Here X is a precision value and Y is scale   values. | 
| 
Double | 
DOUBLE | 
It is a double precision and used for floating point number. | 
| 
Float | 
FLOAT(X) | 
It is a floating point values like (2.3, 1.5 etc.) and X is precision   value. | 
| 
Character varying | 
VARCHAR2(X) | |
| 
Character | 
CHAR(X) | |
| 
varchar(max) | 
VARCHAR(MAX) | |
| 
Bit varying | 
BIT VARYING(X) | |
| 
Bit | 
BIT(X) | |
| 
Date | 
DATE | |
| 
text | 
TEXT | |
| 
Time | 
TIME | |
| 
DateTime | 
DATETIME | |
| 
Timestamp | 
Timestamp | |
| 
smalldatetime | 
SMALLDATETIME |