An obstacle is something that blocks your path or makes it harder to reach your goal. If a fallen tree blocks the hiking trail, that tree is an obstacle. If your family needs to save money for a vacation but unexpected car repairs come up, those repairs are an obstacle to your plans.

Obstacles can be physical things you have to get around, like hurdles on a track or a locked door when you've forgotten your key. They can also be challenges that aren't objects at all: not understanding fractions might be an obstacle to solving a word problem, or shyness might be an obstacle to making new friends at school.

When you face an obstacle, you have choices: find a way around it, remove it if you can, or develop new skills to overcome it. A rock climber encountering a difficult section of cliff faces an obstacle. An inventor whose first prototype doesn't work faces an obstacle, too.