The entire operation in Gaza has been terrorism this entire time, much more than it is "war." That's why I tend to put the word in quotes whenever I am talking about it. If you stop and think for a second, "war" fits the description of what they're doing pretty badly overall.
Deliberate attempts to prevent food aid to put pressure on the civilian population, and specific destruction of important civilian targets like hospitals and universities, as well as the explicit linkage of an end to Israel's attacks with particular goals like removing Hamas or particular terms in the peace agreement, being key elements. A war against armed opponents that are part of an organized apparatus whether state-sponsored or otherwise would look very different from what Israel is doing.