This could be anything. We don't really have enough info to tell. Your location would go a very long way in helping us help you. Please provide it in the avatar section to the left of your posts.
As for this particular tree, might be a Texas live oak (quercus fusiformis), but more likely it's something else. Texas live oaks are "live"--as in evergreen through the winter--for the most part. They drop leaves in spring as new growth emerges. Doesn't mean all the leaves remain on the tree in winter, but I'd expect more to be here if this were a live oak. The leaves that are on this plant are not lobed like Texas live oak leaves tend to be and they look like they're paired oppositely not alternately on the stem as fusiformis leaves are. These are more in line with hawthorn, or a deciduous holly. Again, your location would help tremendously in narrowing things down.