Hi - Based on the growth habit, color, and season, there's a good chance this is Poa trivialis, which is becoming more common in residential turf. Two other grasses that are similar and have a wider leaf blade are orchardgrass and dallisgrass. They can be difficult to tell apart without the presence of the flower heads (the most obvious distinguishing feature). These links show photos of each of these plants and describe the features to look at closely (e.g., whether the leaves are folded, have hairs or not, characteristics of the root system, etc.).
Roughstalk bluegrass

Orchardgrass
Dallisgrass


From a management perspective, these are all perennial weeds, and they are the most difficult to control in a lawn because there is no selective product that will just kill the weed grass and not your turfgrass. You could decide to just live with it and have it be another grass that's part of your lawn, hand-pull or dig the plants out, or spot-treat them with an herbicide. Refer to our page about the use of herbicides for post-emergent control of grassy weeds, and the precautions you should take if you decide to use an herbicide. https://extension.umd.edu/resource/herbicide-options-managing-common-lawn-weeds-maryland You will then have to overseed to repair the bare areas. 

Christa