That is correct. Ethnic cleansing is the act and genocide is a method. The reason it is important to make the distinction is because somebody, in this case Israel, can ethnically cleanse an area without necessarily committing genocide. Because there was no mass murder, no genocide, the media tends to shy away from using the term ethnic cleansing even though it definitely happened.

Jack wants to occupy the house. Jack scares the inhabitants away with threats of violence. Jack occupies house. That’s ethnic cleansing without genocide.

Jack wants to occupy the house. Jack kills the inhabitants of the house. Jack occupies house. That’s ethnic cleansing with genocide.

EDIT: Autocorrect is evil.