Hi,
Data science is simply defined as an interdisciplinary field of study which uses scientific processes,  approaches , methods,  systems and algorithms to extract requisite insights and information from structured and unstructured data.
Syllabus of data science is mainly of three components- big data , machine learning , modeling in data science.

Here is the complete Data Science Syllabus:

Introduction to Data Science

Mathematical & Statistical Skills

Machine Learning

Coding

Algorithms used in Machine Learning

Statistical Foundations for Data Science

Data Structures & Algorithms

Scientific Computing

Optimization Techniques

Data Visualization

Matrix Computations

Scholastic Models

Experimentation, Evaluation and Project Deployment Tools

Predictive Analytics and Segmentation using Clustering

Applied Mathematics and Informatics

Exploratory Data Analysis

Business Acumen & Artificial Intelligence

Hope it helps...