What programming operation involves joining two string values together?

The operation that involves joining two string values together is known as concatenation. This term is widely used in programming to describe the process of linking strings end-to-end to form a new string. For example, if you take the strings "Hello" and "World" and concatenate them, the result would be "HelloWorld". Concatenation typically uses specific operators or functions depending on the programming language, such as the + operator in languages like Python and Java or functions like concat() in others.

The other terms in the options do not accurately describe this operation. Merging usually implies combining data structures or collections rather than just string values. Branding is unrelated and generally refers to marketing concepts or identity representation rather than programming functions. Jointing isn't a standard term used for string operations in programming contexts. Thus, concatenation is the correct concept that directly relates to combining two strings.