implicit vs explicit

Database
Enthusiast

implicit vs explicit

Hi
Can anybody explain difference following things
1)implicit transactions in Tera data mode
2)explicit transaction in Tera data mode

also are following 2 syntax different
i suppose following syntax are same and under explicit transacion

1) BT;
DEL;
INSERT;
ET;

2)BT
;DEL
;INSERT
;ET;

please clarify.....