The fraction 73/100 is equal to 73.00% when expressed as a percentage. This means that if you had a pie chart divided into 100 slices, 73 of those slices would be filled in. It's a way to represent parts of a whole, where the whole is considered to be 100%.
In everyday life, you might see 73% used in various contexts. For example, a weather forecast might say there's a 73% chance of rain tomorrow. Or a student might score 73% on a test, meaning they got 73 out of 100 questions correct. This percentage is pretty close to three-quarters, which would be 75%, so it's a fairly high portion of the total.