Where are you located? Depending on location, some turf grasses do go dormant in winter, producing that brown, dead look. And many times, homeowners with those sorts of lawns do overseed with another type of temporary grass to maintain color in winter.

If in a completely different location, what you are illustrating with the photo could be another, more complicated lawn issue that would require an entirely different approach. Knowing where you are located is really critical to providing any meaningful advice

Also, that photo is from too geat a distance to determine if weeds play a role at all in the brown appearance. Can you get a closer image of what exactly is growing there??

I'm located in southeast Missouri. This is the best Photo I can get if it, but it's all over the yard, greener in some spots

What species of grass is it?

What has your weather been like?

What is the soil like? What is the soil pH? What are the nutrient levels?

Many grass species that grow in SE Missouri will go dormant, turn brown, if the weather is not conducive to growth. Hot and dry, cold and dry, lack of soil nutrients, soil pH out of range, and a number of other problems all can influence whether grasses grow or go dormant.