1 Introduction
2 Similarity of Neural Network Models
2.1 Representational Similarity
2.2 Functional Similarity Measures
2.3 Relationship Between Representational and Functional Similarity
3 Representational Similarity Measures
4 Functional Similarity Measures
5 Analyses of Similarity Measures
6 Application
7 Discussion and Open Research Challenges
8 Neural Network Similarity Beyond This Survey
9 Conclusion