A solder-less connector are devices that have plug and socket connectors and fast-on or quick-disconnect terminals. A wire crimper is used to attach terminals by inserting the stripped end of a stranded wire into a portion of the terminal, which is then mechanically deformed / compressed (crimped) tightly around the wire. The crimping is accomplished with a special crimping pliers.
A blade connector is a type of single wire connection using a flat blade which is inserted into a blade receptacle. Usually both blade connector and blade receptacle have wires attached to them either through soldering of the wire to the blade or crimping of the blade to the wire. In some cases the blade is a manufactured part of a component (such as a switch or a speaker unit) and a blade receptacle is pushed onto the blade to form a connection.
A common type of blade connector is the "Faston". While Faston is a trademark of Tyco Electronics, it has come into common usage. Faston connectors come in male and female types. They have been commonly used since 1970s.
Ring and Spade Terminals
The connectors in the top row of the image are known as ring terminals and spade terminals (sometimes called split ring terminals). Electrical contact is made by passing a screw or bolt through them. The spade terminal form factor facilitates connections since the screw or bolt can be left partially screwed in as the spade terminal is removed or attached. Their sizes can be determined by the size of the conducting wire AWG and/or the Screw/Bolt diameter size designation.