Google's Panda update is a different release than Penguin. Panda is geared toward duplicative, thin, or spun content on websites Penguin is much harder to understand, focusing on backlink patterns, anchor text, and manipulative linking tactics that provide little value to end users. To make matters worse, Google likes to take large manual actions just prior to major algorithm updates.
In August 1, 2018 has a core update and it's different. The way I understand it, a core update is a tweak or change to the main search algorithm itself. You know, the one that has between 200 and 500 ranking factors and signals (depending on which SEO blog youre reading today). What a core update means to me is that Google slightly tweaked the importance, order, weights, or values of these signals. The simplest way to visualize this would be to imagine 200 factors listed in order of importance. Now imagine Google changing the order of 42 of those 200 factors. Rankings would change, but it would be a combination of many things, not due to one specific factor or cause. Basically, it means Google may have changed the way they calculate term importance on a page, or the the weighting of links in PageRank, or both, or a whole bunch of other factors that they cant talk about without giving away the algorithm.