Beefcake is a word used to describe a man who is very strong and muscular.
It's like when you see superheroes in movies or cartoons - they have big muscles and look really strong, right? Well, that's kind of what beefcake means. If someone is a beefcake, it means they work really hard to build up their muscles and make themselves look really fit and strong.
Sometimes people might use the word beefcake to describe a man they find attractive because of his muscles. But remember, it's important to appreciate people for who they are on the inside too - not just what they look like on the outside!