Cache and Cookie both are used for the temporary storage at client side and helps to improve website performance & accessibility but both have different purposes.

Cache

Cookie
Whenever you visit any website first time, its page elements are downloaded and stored in a cache folder and if you have already visited that website, its elements might be already exist in cache folder. This improves your browsing speed and helps the web pages to be quickly loaded. Cookie is a small piece of info or simple text file which stores temporary information that helps in tracking session of user’s browsing ,managing session and also helps in client server communication. When you visit any website, it creates cookie at client side and communicates with server each time when page is requested.
Cache can store images, script files, text, audio, video, flash, banners, etc. Cookie can only stores text based data like IP address, session number, password, user visit history, no. of pages visited, etc.
Cache does not get expired automatically, user has to remove it manually from client side. Cookie automatically gets expired after sometime.
Cache can store different type of data as mentioned so consumes large amount of space on client machine. Cookie is text file so it does not consume so much space on client machine.
Cache stores different types of data so it can have malicious data. Cookie is simple text file so can not contain any virus or malicious data.