What are some accomplishments from the Qin Dynasty?

1. The weights and measures as well as written characters were standardized then. During Qin, the round coin with square hole (Ban Liang Coin) were official coins and the Qinzhuan, the standard font were their characters.
2. The slavery was abolished due to the Reform of Shang Yang.
3. The private ownership of land was first carried out then, which made people lived a relatively steady life.
4. Qin Shi Huangdi ordered to link and build the Great Wall, which has been a great atttaction by now.
All for your reference!

Thank you so very much. Now I'm not so confused.

Here are some inventions of that time.

Legalism
Standardized writing and language
Standardized money
Standardized system of measurement
Irrigation projects
Building of the Great Wall
Terra cotta army
Expanded Network of Roads and Canals
Multiplication Table