"Highlights" are different regions/tones in the two panels. In the basics panel "whites" are the brightest section of the histogram with highlights second. On the curves panel highlights are the brightest region, with "lights" second.
The region of the histogram each adjustment affects is fixed in the basics channel. But the regions can be modified in the curves panel by moving the the dividers at the bottom.
And the basics panel adjustments are more localized, whereas the tone curve adjustments are more general/global:
“In the Basic panel, Highlights and Shadows serve as the primary tone mapping controls. They are sensitive to image content and edges within the image. They are effective at adjusting overall (global) contrast, while preserving local contrast. They are useful for tone mapping high dynamic range (HDR) images. They automatically expand their effective range when applied to high-contrast images (like HDR images), and automatically reduce their range when applied to low-contrast (e.g., foggy) images. The underlying mechanism behind Highlights and Shadows is generally known as “local adaptation,” which means that the controls do different things in different parts of the image. It’s as if each pixel has its own tone curve. In short, the Highlights and Shadows controls in the Basic panel are very “dynamic” in nature.
In the Tone Curve panel, Highlights and Shadows are much more straightforward or “direct” controls. They simply adjust a portion of the overall global tone curve. Unlike the controls of the same name in the Basic panel, the ones in the Tone Curve panel act globally, and do the same thing at every pixel. Their range is always fixed. They do not adapt automatically to image content in any particular way.
For these reasons, I recommend using Highlights and Shadows first in the Basic panel for primary adjustment, and then (optionally) using Highlights and Shadows in the Tone Curve for fine-tuning (later in the workflow). Put another way, we have the more adaptive, dynamic, “smarter” controls in the Basic panel, and the more low-level, direct, “standard” controls in the Tone Curve panel.”
Eric Chan, Adobe Principle Scientist working on Adobe Camera Raw and Lightroom (Ca 2015)