Is there any difference between ftp and sftp tranfser types in terms of transfer modes (binary, ASCII)? In sftp transfer do we still have binary and ASCII transfer option or it has its default mode whether we choose or not.
SFTP works on top of ssh and does not have equivalent for FTP transfer mode. In other words, SFTP transfer is always binary, byte to byte exact.
You should not confuse SFTP with FTPS though. FTPS is much like old FTP, but over SSL, and is supported by some servers. Because it is still old FTP wrapped in SSL, it does support notion of transfer mode (ascii or binary). However, FTPS servers are very rare in the wild, and I think it is very difficult to actually encounter one.