Kingdom: Animalia 
Phylum: Arthropoda 
Class: Arachnida 
Order: Araneae 
Suborder: Araneomorphae 
Superfamily: Pholcoidea
Family: Pholcidae
Species: P.phalangioides
Scientific Name: Pholcus phalangioides
Common Name: Daddy Long Legs, Granddaddy long-legs spider, Daddy long-legs spider, Daddy long-legger, Cellar spider, Vibrating spider, Daddy longlegs spider.

The Daddy long legs are an introduced spider during the early European colonial period. Pholcids are fragile spiders, the slender body being 2–10 mm in length with very long legs which may be up to 50 mm long. Pholcids are web-weaving spiders and are distributed worldwide and were accidentally introduced to New Zealand. They hang inverted in messy, irregular, tangled webs. These webs are constructed in dark and damp recesses, in caves, under rocks and loose bark, abandoned mammal burrows in undisturbed areas in buildings and cellars, hence the common name "cellar spiders". However, Pholcids are also quite commonly found in warm, dry places, such as household windows.  
When a victim is trapped in the web it immobilises it by wrapping it in silk, not like other spiders that use venom.

There is an often-repeated urban myth that states ‘the daddy longlegs is the most poisonous spider in the world, but it can’t bite you because its fangs are too small’. The myth is incorrect at least in making claims that have no basis in known facts. There is no reference to any pholcid spider biting a human and causing any detrimental reaction. If these spiders were indeed deadly poisonous but couldn't bite humans, then the only way we would know that they are poisonous is by milking them and injecting the venom into humans. 

Daddy Long Leg spider Pholcus phalangiodes-001.JPG 

A female and her spiderlings.Cellar spider Pholcus phalangioides .jpg

A photo of a Pholcus phalangioides that has immobilises a whitetail spider (Lampona cylindrata) by wrapping it in silk. 
Pholcus phalangioides Daddy Long Legs spider.JPG

Pholcus phalangioides Daddy Long Legs spider-001.JPG Pholcus phalangioides Daddy Long Legs spider-002.JPG

A whitetail spider (Lampona murina) wrapped in silk. The white tip at the rare of spider abdomen is visible.
Pholcus phalangioides Daddy Long Legs spider-003.JPG

Another spider meal wrapped up.
Daddy longlegs spider Pholcus phalangioides-001.JPG

A female Pholcus phalangioides carrying her egg sac

Female Pholcus phalangioides carrying egg sac.JPG

Pholcus phalangioides Daddy Long Legs spider-004.JPG

Daddylong legs head.jpg

A video showing a Daddy long leg spider catching a whitetail spider

Thanks to Wikipedia for text and Information: