What does it mean that it is not freestanding?

Tech Specs:

Material:

[Body] 70D 190T Nylon ripstop; [floor] 68D 210T nylon taffeta with 2000mm PU coating; [fly] 68D polyester taffeta with 1500mm PU coating and DWR 

Freestanding:

No 

Poles:

2 

Pole Material:

Atlas 7001 aluminum 

Doors:

1 

Clip/ Sleeve:

Clip 

Floor Space:

30sq ft (2.8sq m) 

Interior Height:

38.5in (97cm) 

Vestibule Space:

10 sq ft (0.9 sq m) 

Seam Sealed:

Yes 

Bathtub Floor:

Yes 

Ventilation:

Mesh window, door 

Packed Size:

22.2 x 5.9in (57 x 15cm) 

Max Weight:

4lb 8oz (2040g) 

Recommended Use:

3-Season backpacking 

Warranty:

Lifetime 

Country of Origin:

China