The Bundestag is the parliament elected directly by the people.
The Basic Law rules that the Bundestag elects a president, vice-presidents as well as secretaries and gives itself an agenda (Article 40 I GG).
The president calls up the Bundestag and leads the meetings, has an advisory vote in all committees and exercises the house right and the rights of the police in the building of the Bundestag. He also represents the Bundestag in the public. He is elected for the duration of the legislative period.
Formed by the president and the vice-presidents it advises internal affairs of the Bundestag.
The secretaries support the president in the lead of the Bundestag meetings, they receive for example word messages and determine voting results.
The Council of Elders consists of the President of the Bundestag, the vice-presidents and further 23 Members of Parliament, designated from the parliamentary groups according to the proportion of the number of their members. It supports the president at his work. For example it communicates the schedule between the parties or prepares the agenda of meetings (§ 6 GOBT). In addition it decides the internal affairs of the Bundestag.
The permanent committees are smaller groups of delegates, who are concerned with special political topics. Here the actual special work of the parliament like the discussinon of bills, is done.
The following obligation committees are defined by the Basic Law:
Besides there are advisory committees,usually one per ministry, so there are altogether about 20 permanent committees.
Article 44 I
The Bundestag shall have the right, and on the motion of one quarter of its Members the duty, to establish an investigative committee, which shall take the requisite evidence at public hearings. The public may be excluded.
Article 45
The Bundestag shall appoint a Committee on European Union Affairs. It may authorize the committee to exercise the rights of the Bundestag under Article 23 vis-à-vis the Federal Government.
Article 45 a I
The Bundestag shall appoint a Committee on Foreign Affairs and a Committee on Defense.
Article 45 c I
The Bundestag shall appoint a Petitions Committee to deal with requests and complaints addressed to the Bundestag pursuant to Article 17.
Upon the request of a quarter of the delegates investigative committees can be established. These investigative committees do not exist permanently but for the duration of the investigation.
A constant "one-man committee of inquiry" for democratic control of the German Federal Armed Forces.
Parliamentary groups are groups of at least 5 % of the Members of the Bundestag, who belong to the same party or different parties which do not compete with each other in a Land.
Their aimes are clarifying of the political will and / or better penetration of the political goals of their members. Parliamentary groups have substantial rights of participation and request according to the agenda of the Bundestag, in addition the occupation of the committees depends on relative strengths of the parliamentary groups.
The plenum is the whole of all delegates
A coalition is an union of several parties for the common formation of a government, if no party alone achieved the absolute majority, which is necessary for the formation of the government.
The opposition includes all parties, which do not belong to the coalition.
The function of the Bundestag concretized by the agenda (Article 40 I GG), could be described by these principles:
The Bundestag is able to make a decision, if more than half of its members are present (§ 45 GOBT).
To determine a majority, the delegates vote. One votes either by hand-signal or rising. If there are doubts, whether a majority was reached or not, the vote will be repeated with a special procedure, called "Hammelsprung" (mutton jump).

During the "Hammelsprung" the delegates first leave the plenary assembly hall and then occur again to the hall individually by one of three doors, which are marked by "yes","no"and "abstention". When occurring they are counted by the secretaries.
The name "Hammelsprung" comes from a door, which was in the Reichstag building. On this door a scene from the Odyssey by Homer is shown in which Odysseus free himself and his companions with muttons from the captivity at a giant.
In addition there are elections by name with voting cards and secret elections with voting cards and election cabs in the Bundestag.
If a delegate from the Bundestag retires, for example because he dies or abdicates his mandate, then a candidate advances from the national list of the party, for which he was elected into the Bundestag. This applies in the same way to the direct elected delegates and those elected via a national list.
The Bundestag cannot dissolve itself. It can be dissolved by the Federal President in two cases:
In both cases new elections must take place within 60 days (Article 39 I S 3 GG).
Article 63 IV
If no Federal Chancellor is elected within this period, a new election shall take place without delay, in which the person who receives the largest number of votes shall be elected. If the person elected receives the votes of a majority of the Members of the Bundestag, the Federal President must appoint him within seven days after the election. If the person elected does not receive such a majority, then within seven days the Federal President shall either appoint him or dissolve the Bundestag.
Article 68 I
If a motion of the Federal Chancellor for a vote of confidence is not supported by the majority of the Members of the Bundestag, the Federal President, upon the proposal of the Federal Chancellor, may dissolve the Bundestag within twenty-one days. The right of dissolution shall lapse as soon as the Bundestag elects another Federal Chancellor by the vote of a majority of its Members.