Latex is a milky liquid found in many plants but is not the same as sap. It can cause an allergic reaction for some people.
One use for latex is in the production of rubber. The rubber tree (Ficus elastica), a type of fig tree, was an original source of latex to be processed into rubber.
The current source for commercial rubber is the Pará rubber tree (Hevea brasiliensis). Although the tree hails from the Amazon rainforest, it was brought to Southeast Asia, which now produces most of the commercial latex.
To collect the latex, trees are tapped (much like maple trees) and the latex drops into cups or buckets. Chemicals are added to keep the latex from stiffening up. It may go through processes like coagulation, centrifugation, compounding, vulcanization, stripping, leaching, chlorination, and lubrication in creating the final latex product.