Can someone explain the difference between Sabra and Israeli?

Same as wombat_13 said, with the following changes:

Sabras can also be Israelis who weren't born here, if they fought a war here.

"Sabra" is a cactus pear. Native born Israelis call themselves this, because they are prickly on the outside (rude and tough), but tender sweet on the inside (care for others), just like the cactus pear.

A great example of a true Sabras is Yitzchak Rabin. (He was so RUDE, and he wasn't born here, but he was a general in the army.)

sabra is a native born israeli. an israeli can be someone who has moved there,or born there. but most of the time, people are just refered to as israeli.

sabra is slang for native israeli, it refers to a certain personality type, like strong and independent, and sometimes perceived to be rude even though they aren't... Sabra is named after a prickly pear, that was harsh on the outside sweet on the inside

Sabra is native born. Israeli can refer to either native born or immigrant

Sabras are Jews born in Israel.