Discrete mathematics is focuses on topics such as sets, logic, relations, functions. Here are some basic concepts in discrete mathematics:


Sets: 

A set is a collection of distinct elements. Sets can be represented using curly braces {}. For example, {1, 2, 3} represents a set containing the elements 1, 2, and 3.


Logic: 

Logic deals with the study of reasoning and argumentation. Propositional logic is concerned with the evaluation and manipulation of logical statements using logical operators such as AND, OR, and NOT.


Relations:

 A relation is a set of ordered pairs that establishes a connection between two sets. It describes how elements in one set are related to elements in another set. Examples of relations include equality, less than, and divisibility.


Functions:

 A function is a relation between two sets where each input from the first set corresponds to exactly one output from the second set. Functions are often denoted as f(x) = y, where x is the input and y is the output.


Graph Theory: 

Graph theory deals with the study of graphs, which consist of vertices (or nodes) connected by edges. Graphs are used to model relationships and connections between objects. They have applications in computer science, optimization, and network analysis.

These are just a few basic concepts in discrete mathematics. The field is broad and covers many other topics, including number theory, algorithms, formal languages, and automata theory.