There are many significant differences between modern sculpture and classical sculpture, which are mainly reflected in the following aspects:

1. **Style and form**:

- **Classical sculpture**: usually emphasizes symmetry, proportion and idealized human representation, often influenced by Greek and Roman art, and pursues perfect form and harmonious composition.

- **Modern sculpture**: diverse styles, may adopt abstract, expressionist or other non-traditional forms, emphasize personal expression and innovation, and often break traditional aesthetic standards.

2. **Materials and technology**:

- **Classical sculpture**: commonly uses traditional materials such as marble and bronze, with relatively fixed production processes, emphasizing carving and casting techniques.

- **Modern sculpture**: materials are more diverse, including glass, plastic, metal, wood, etc., and even recycled materials are used. The technology may also combine emerging technologies such as 3D printing.

3. **Theme and content**:

- **Classical sculpture**: mainly based on mythology, historical figures and religious themes, conveying universal values and ideals.

- **Modern sculpture**: the theme is more extensive, which may involve society, politics, personal emotions, etc., and often reflects the problems of contemporary society and the personal views of artists.

4. **Audience participation**:

- **Classical sculpture**: Usually static, audience participation is relatively limited.

- **Modern sculpture**: Many modern works encourage audience interaction, and can even be installation art, where audience participation becomes part of the work.

5. **The role of the artist**:

- **Classical sculpture**: Artists are often seen as skilled craftsmen, emphasizing the mastery of traditional skills.

- **Modern sculpture**: The role of the artist is more diverse, and may be a guide of thought, a social commentator, emphasizing the importance of creativity and concepts.

In general, modern sculptures show greater freedom and diversity in form, material, subject matter, and audience interaction, reflecting the cultural and social background of different times.