Technical translations are a specific subset of translations that deal with more logical and well defined subjects. This can include topics such as scientific analysis or medical illustrations. Translations in these areas are a valuable commodity and there are many businesses seeking translators who are able to do the job.
For example it can be more difficult for a business to find a technical translator for a legal subject, than for a topic about construction, simply because of the amount of knowledge that is required to produce a well informed translation on the subject. It is true that translators are seldom fully knowledgeable about the subjects they translate, creating perfectly logical and readable translations on those topics. But It is still difficult to get hold of translators who are able to research the topics to an extent that the translation produced is one of clarity and high quality.