Hawker - Somebody who travels around selling stuff; usually by shouting and yelling. Vendor - Vendors can be two things. Either 1) Somebody who sells stuff on the streets i.e. Hotdogs (I think you might see some in Newyork), ice cream etc. Or 2) Can also be known as a supplier. Basically, a company (or person) that sells stuff to a store, or person etc. Shop Assistant - A person in a shop who helps customers purchase stuff from the store, and in general, helps around the shop. Sales clerk - When I think of a sales clerk, I usually think of somebody running the cash register. But I suppose in some cases, they help the customers (ex. give information about a product). It's similar to a shop assistant but not quite the same thing. Hope I helped! If you have any questions feel free to ask. :)

A hawker is a person selling something loudly and in a showy manner. If somebody is hawking something, they are doing something to get noticed , and talking in a loud voice to get attention. They are usually outdoors. A vendor is anybody selling something. It can refer to a whole company or just a salesperson from that company. A shop assistant is some person at the lowest level of sales. This is an entry position. They may persuade you to buy something, but they are also there to arrange the goods and ring up the sale. They are considered the next rung below a full salesperson. A sales clerk has many of the duties of a shop assistant. They concentrate more on the sale than other duties, but many times, the job is the same.