Difference between sulfuric clouds and sulfuric haze (on Venus)?
According to Wikipedia, haze is an atmospheric phenomenon in which dry particulates obscure the clarity of the sky.

Whereas haze is thought of as a phenomenon of dry air, mist formation is a phenomenon of humid air.

However, haze particles may act as condensation nuclei for the subsequent formation of mist droplets; such forms of haze are known as "wet haze".

In meteorological literature, the word haze is generally used to denote visibility-reducing aerosols of the wet type.

According to Wikipedia,  a cloud is an aerosol with a visible mass of liquid droplets, frozen crystals or particals suspended in the atmosphere, and the droplets don't have to be made of water.

This article states that standard cloud models for Venus consider that all clouds and hazes are composed of liquid droplets of sulfuric acid mixed with water, with sulfuric acid making accounting for 75% to 96% by weight of the cloud composition.
However, other minor constituents may make up the cloud particles.

Clearly regarding the mixture of water and sulfuric acid there is no distinction between clouds and hazes on Venus.

In another article it can be seen on images that the altitude from 30-48 km of the atmosphere of Venus is named "the thin haze region ", whereas
the altitude from 48-50 km is called "lower cloud region ". 

The figure on page 14 of the dissertation of Yeon Joo Lee also shows that below the cloud layers there is this "thin haze region" which has almost a thousandfold less extinction coëfficiënt than the clouds above it.

Apparently this huge difference in absorbing the light explains the difference and appearance between sulfuric clouds and sulfuric haze on Venus.

Figure 4 of Bullock and Grinspoon 2001 (paywalled) The Recent Evolution of Climate on Venus (Icarus 150, 1, Mar. 2001, pp 19-37) shows the abundances of H$_2$SO$_4$ and H$_2$O in the cloud region of the atmosphere of Venus. A non-paywalled version can be found with an internet search, but since it does not use https I won't include the link explicitly here.



Explicitely it shows H$_2$SO$_4$ as a gas in the thin haze region and only in the cloud region there is a mixture of water and sulfuric acid liquid.