A bit new to cycling so please pardon my ignorance. All was fine on my bike up until the other day when I engaged the front brake and nothing happened. I had to fully squeeze the brake until it was touching the handlebar before the pads would close. This had never happened before, and the rear brake only needs a small squeeze for the pads to engage. I did squeeze hard on the brake as I was about to miss my turn, but nothing broke or snapped as far as I can see. Please see pictures for the front and rear brakes engaged. Any idea on what has happened?
Work the lever and check that that the caliper is moving - that will tell you that the cable is attached and has not broken.
Make sure the little lever on the caliper that spreads the pads to let the wheel come out of the bike isn't engaged
Inspect the cable run from lever to caliper, make sure the housing is properly inserted into the lever and all frame stops.
If that all checks out the cable may have slipped through the pinch bolt on the caliper. Undo the pinch bolt to free the cable, verify the lever is pulling cable by pulling on the cable and and working the lever, reattach the cable. You can refer to this Park Tool video for installing and adjusting calipers.