Can you tell me what hypoallergenic cosmetics are?

Less likely to... Less likely to cause an allergic reaction (in the general population). What this means for each individual depends on their specific autoimmune response to certain ingredients in a product. For best results determine your allergies (if any), & avoid products to which you react. Consult your allergist/immunologist for the details :).
Slight risk. Hypo means low thus they are low on the scale of causing sensitivity or allergic to.
Variety of things. In general, they are cosmetics that are less likely to induce allergenic (hypersensitivity) changes when exposed to the skin. Typically, they may be devoid of fragrances and harsh dyes, etc...