Any computer that you have is something that you want to run fast so that you can work or play on it without waiting. When you own a Mac, these are generally pretty fast machines. There are things that you can do that will help your Mac run faster so that you can get better performance out of it and wait less.
Make sure that you have some disk space. There are all sorts of background activities going on that will require disk space for backups and temporary files. If you are almost out of disk space, you will be running your computer much slower than you should be. Delete some things for better performance.
Add some RAM to your machine. RAM is the simplest upgrade to make and will be the cheapest for you. This alone makes a huge difference as your computer will be running much faster.
Use your Activity Monitor to find the programs and applications that are taking up too much CPU or RAM. You can get to this application under Applications then Utilities. Turn off things that are taking up your system's resources so you can get better performance out of it.
Make sure you use less applications at once when you are running your system. Many times Mac users get into the bad habit of just minimizing things as opposed to closing them. This means everything is sharing resources meaning each individual program will be running slower than it could be.
Get your system updates. These will help improve the security and performance of your operating system. This should be done at all times.
At times the loss of performance might be a heat issue. If your computer gets too hot, then it will run slower. Dust out the vents to get better airflow. If you have a laptop, use a cooling pad to lower the CPU temperature so that it will run better.
While your Mac is a fast machine, there are times when you would like more performance. Find out what you can do that will help improve your computer's speed.