CHAR(size)
Store char strings of fixed length. size determines no. of characters the field can hold.The remaining chars are padded with spaces.
e.g. if CHAR(10) and you inserted sanjay then remaining 4 chars will be spaces.
VARCHAR(size)
This datatype is used to store variable length alphanumberic data. Maximum chars is 2000 chars.
DATE
Represent data and time. Standard format is DD-MON-YY as in 21-JUN-02.To enter date other than standard format,use ORACLE DATE functions.
NUMBER (P,S)
Store numbers fixed or floating-point. P= precision,S=scale = no. of decimal points.
NUMBER(4,2)= 99.99
LONG
Variable length char strings upto 2 GB.
RAW/LONG RAW
Store binary data such a picture file,image file.
Max length of RAW=255 bytes.
Max length of LONG RAW=2BG.