1, version difference: different covers represent different versions or different version features. Publishers will launch different cover versions at different times to attract different readers or meet different market demands.
2. Distribution in different regions: Sometimes publishers will customize different covers for different regions or different markets. This is due to the consideration of readers' aesthetic preference or cultural background in different regions.
3. Special edition or limited edition: Some covers are special editions or limited editions with special designs or features to increase their collection value or attract readers' interest.
4. Multiple versions are released at the same time: Sometimes publishers will release multiple versions with different covers at the same time to meet the different needs and preferences of readers. Therefore, the "Ancient Poetry 169" published by Snail Sinology Museum has two covers, for the above reasons. Ancient Poetry 169 is a collection of 169 classical poems and classical Chinese in ancient China literature.