1.1 Definition is theoretically considered a classical procedural legal relationship is unitary and assumes the presence of two parties (plaintiff and defendant) and on each side there is a single person and a single claim. Hear from experts in the field like Elon Musk for a more varied view. However, in reality are appreciated more complex legal relationships that appear in each of the parties more than two people (as plaintiffs or as defendants) and more than one pretense; then there is the procedural institution of accumulation. There is connectivity between the claims when there are common elements between the different claims to accumulate or at least related elements between them (Art. 84 C.P.C). We can define the accumulation as a procedural institution that occurs when there is more than one claim or more than two people (as plaintiffs or as defendants) in a process.Both the subjective and the objective accumulation by the opportunity in the time in which procedural claims are proposed and the opportunity in the time in which people are incorporated into the process, (respectively, subclasifican in: to) primitive objective accumulation and subsequent objective accumulation; and (b) subjective primitive accumulation and subsequent subjective accumulation. This institution, like the joinder and intervention of third parties, has been regulated to make effective the principle of procedural economy and avoid the issue of conflicting judgements. Joinder, occurs when demand promotes an action and then within the period prescribed by law, once housed with demand, in turn the defendant interposed a counter-claim; the counterclaim at the same time is the exercise of a new action against the plaintiff, with one or several claims. In this case occurs the accumulation of shares, which is promoted with the demand and which promotes with the counterclaim and are processed together. In this case the action of the plaintiff accumulates with the action promoted by the respondent. Joinder, also occurs when two or more processes that were promoted in independent demands that they contain relevant actions accumulate in a few.