SQL*Loader provides the following methods to load data: 

Conventional Path Loads, Direct Path Loads, External Table 
Loads 

Conventional Path Loads: During conventional path loads, 
the input records are parsed according to the field 
specifications, and each data field is copied to its 
corresponding bind array. When the bind array is full (or 
no more data is left to read), an array insert is executed. 

Direct Path Loads: A direct path load parses the input 
records according to the field specifications, converts the 
input field data to the column datatype, and builds a 
column array. The column array is passed to a block 
formatter, which creates data blocks in Oracle database 
block format. The newly formatted database blocks are 
written directly to the database, bypassing most RDBMS 
processing. Direct path load is much faster than 
conventional path load, but entails several restrictions. 

External Table Loads: An external table load creates an 
external table for data in a data file and executes INSERT 
statements to insert the data from the data file into the 
target table.