Structure in mathematical logic is like playing with Legos. You have a bunch of small building blocks that you can connect together to make something bigger, like a spaceship or a castle. In math, these building blocks are called symbols or elements, and they might include things like numbers or shapes or even more abstract concepts.
When we talk about a structure in math, we mean a specific set of these symbols, along with some rules for how they can be put together. For example, you might have a structure that includes the symbols 0, 1, +, and ×, along with the rules that let you add and multiply them.
Just like with Legos, the possibilities for what you can create with a structure are pretty much endless. You could use that same structure to build something as simple as 1 + 1 = 2, or you could use it to create complex equations or systems of equations.
The other cool thing about structures in math is that they can be compared to each other. You might have two different structures that both use the same symbols, but with different rules. For example, you could have a structure that uses the same symbols as before (0, 1, +, and ×), but this time the rules say that 1 + 1 = 0.
By looking at different structures and comparing them to each other, mathematicians can explore concepts like symmetry, completeness, and consistency. It's like they're exploring a big world of Legos, figuring out how all the pieces fit together and what they can create.