I'll travel from Thailand to China for 2-3 days. I need a Visa for China, or?

I visit a company there.

So I go to the Chinese embassy. Do I need a business or tourist visa?

What documents?

(I am Austrian if that makes a difference)

Notice about Material Requirements for Application of Business and Tourist Visa to China 2012-07-15

Since 15th July 2012 onwards, applicants for Business Visa ("F" visa) and Tourist Visa ("L" visa) should submit the following supporting documents:

1, Business Visa ("F" Visa)

An Invitation Letter or a Confirmation Letter of Invitation issued by a Duly Authorized Unit. Or an invitation letter issued by a non-authorized Chinese unit.

2,Tourist Visa ("L" Visa)

An Invitation Letter for Tourist Group or Tourist issued by a Duly Authorized Tourist Agency. Or an invitation letter issued by a non-authorized Chinese unit.

Non-authorized Chinese Unit refers to Chinese local government or a Chinese company, corporation, institution and individual other than Duly Authorized Unit.

More here.

Notice about Material Requirements for Application of Business and Tourist Visa to China 2012-07-15

Since 15th July 2012 onwards, applicants for Business Visa ("F" visa) and Tourist Visa ("L" visa) should submit the following supporting documents:

1, Business Visa ("F" Visa)

An Invitation Letter or a Confirmation Letter of Invitation issued by a Duly Authorized Unit. Or an invitation letter issued by a non-authorized Chinese unit.

2,Tourist Visa ("L" Visa)

An Invitation Letter for Tourist Group or Tourist issued by a Duly Authorized Tourist Agency. Or an invitation letter issued by a non-authorized Chinese unit.

Non-authorized Chinese Unit refers to Chinese local government or a Chinese company, corporation, institution and individual other than Duly Authorized Unit.

More here.

I read that, but what does it mean practically?