ODM = Original Design Manufacturer An ODM is a company that designs and manufactures products to a specification that is at the least partially supplied by a third party, usually another manufacturer, a brand or a trading entity and the product bears the brand name of the 3d party. This is very similar to what an OEM does but the difference lies in the specification supplied by the 3d party in the case of an ODM product, that results in a unique product although it may bear a strong resemblance to other products from the manufacturer while in the case of an OEM you are getting a product that is absolutely identical to something that may already be on the market under other names and sometimes with different fascia's. Not to be confused with companies that do not design products but just manufacture them for the company that designed them, those are referred to as subcontractors.
In the case of an ODM any IP rights to the devices made usually lie with the ODM although they are often split if the amount of specification work is considerable enough, otherwise the IP and warranty issues with an ODM are the same as with an OEM (see below).
For a usage example that illustrates the differences between an OEM and an ODM consider the historical case of USA company Superscope Technologies, in the 1970's, they had 2 lines of products, a cheaper line of products branded Superscope that were bought in from OEM's in Taiwan that were identical to products sold under brands like Realistic, NAD and Atron except for the front fascia and the name plate on the back. In the case of the more upmarket Marantz line from the same company they had an ODM contract with Japanese company Standard Radio that designed and manufactured the Marantz product line with input from Superscope on the specifications of the units, this resulted in a series of unique products.
OEM = Original Equipment Manufacturer An OEM is a company that designs and manufactures products for a third party, usually another manufacturer, a brand or a trading entity and the product bears the brand name of the 3d party. This is not to be confused with companies that do not design products but just manufacture them for the company that designed them, those are referred to as subcontractors.
Please note however that like subcontractors an OEM manufacturer do not sell their products to end users, dealers or distributors and thus are not responsible for warranties or supplying information on older products etc., that responsibility is on the hands of the supplier of the product, furthermore the OEM is usually bound by a contract to their supplier not to give out information on it and thus usually do not answer queries from end users for that simple reason.
They do however own any IP rights to the devices since they are the originators of the design, but that means that the status of the brand that sold the device has no bearing on the intellectual property rights, so even if the company that sold the product originally has ceased trading and their brands and their IP has technically or effectively been placed in the Public Domain you cannot distribute or make use of the device related IP like technical drawings and manuals without permission from the OEM.
Note also that the usage of the term OEM in the automotive industry is completely different from how it is used in the electronics and musical instruments businesses, but in those cases it is used to identify the original seller (i.e. BMW, Saab et al.) not the original manufacturer (Bosch, Lucas et al.).
OEM purchasing agent A type of company or a division of one that handles the logistics of specifying and purchasing products from OEM's. I.e. if your company needs to source any sort of products or services that you intend to sell under your own name you can either seek out and contact the original manufacturing entities yourself and handle the necessary specification creation alongside other issues such as financial transactions, import duties, shipping logistics and local safety regulation compliance, or you can contact a company that handles all of this for you.
It is perhaps surprising but the usage of purchasing agents has actually increased in the internet age rather than diminished, this is primarily due to the proliferation of brands versus manufactures, this has meant that companies are increasingly selling products that they do not have any in-house technical knowledge of so cannot specify them much less make a proper ODM request, in addition the more specialised manufacturers do not advertise nor hold out a webpages etc., so actually finding out who they are and inspecting their factories & processes, especially if they are on another continent can be extremely costly. It therefore makes increased sense to get it through a company that has already performed all these steps. These sort of agents are actually trading companies but from a legal standpoint are more of service entity since everything is done under contract rather than via a goodwill agreement.
OFC = Oxygen Free Copper Copper wires manufactured so that there are no oxygen bubbles inside the wire or rather an absolute practical minimum, the wire is then plated with another material, usually metal and in high end cables qute often silver, to hinder oxidation from the outside. The plating process is not strictly necessary but should improve performance over the long run since copper oxides are bad conductors, silver oxides are however and one of the reasons some people prefer that material despite quite a considerable more cost.
OFDM = Orthogonal Frequency Division Multiplexing A digital broadcasting technique, the signal is sent out as a Spread-Spectrum with quadrature multiplexing but what makes this different from analogue broadcasting is that pulses are modulated over the zero crossing of the pulse that comes before them, the aliasing errors generated by this are ignored by the receiver since it only needs to work out if each pulse is a 0 or 1 with the exact shape of the pulse being of no importance. This technique is used in the European terrestrial digital TV standard DVB to cram 70 channels or more onto a single broadcast signal and recently Siemens has shown a development of the system that can broadcast 360 Mbps in real live conditions.
Osborne Effect Self harm inflicted by a company's marketing department by pre announcing new products while they still have warehouses full of older products or is not yet ready to commence manufacturing of the new product. Named after Adam Osborne, a noted PC & technical writer in the 1970's that founded Osborne Computers on the proceedings of the sale of his publishing business (Osborne & Associates, Inc., a pioneering computer publishing firm), this company went on to become the fastest growing computer company ever, but managed to self-destruct when they pre-announced a revolutionary new version of their computer at the same time as the industry was facing a minor slump.
OTL = Output Transformer Less A design methodology for valve amplifiers but in normal circumstances a transformer needs to be placed between the valves output and the loudspeaker terminals for impedance matching etc. Getting more popular in recent years in search of valve amplifiers with less colouring but in the 40's and 50's most OTL designs were attempting to archive a usable Class B design in search of more output power, but at the time all "Hi-Fi" amplifiers were Class-A.
OTR = Old Time Radio American idiom for recordings from the golden age of radio, which in their case was from the late 1930's into the latter half of the 50's when radio was more a source of information, propaganda and spoken entertainment than a music carrier. TV took over these roles fairly quickly after it's introduction and most spoken word production ceased in the 1950's with the exception of religious and political propaganda broadcasts, although a few stations and broadcast networks did some drama and soap creation into the 1980's.