It simply the bread that is sacred and it represents the body of Christ.
There will be red light or candle near to it, called the Sanctuary light - if lit Jesus is present in the tabernacle.
If the sanctuary lamp is burning the Holy Eucharist is present in the tabernacle.
Consecrated bread only. It's not there to hold anything else.
1) It is actually spelled:Tabernacle. The tabernacle is where the consecrated bread( body of christ) is kept. It usually looks like an expensive treasure box with doors. All Catholic Churches have Tabernacles. Beside the tabernacle there is a light or candle. When this light is lit, it means that the consecrated bread is present inside of the tabernacle.
In the tabernacle.
It signifies that the Blessed Sacrament is present in the tabernacle.
Consecrated wafer is sacramental bread. This is bread that is given in churches.
It is during the offering up in the Catholic Mass by the priest that the bread and wine are consecrated with the repeated words of Jesus Christ at the Last Supper,"This is My Body;This is My Blood" thereby making Jesus Christ present on the altar Body,Blood Soul and Divinity in the consecrated hosts and the Chalice filled with now consecrated wine which is the Blood of Christ. The "reserved Eucharist" you speak of is the consecrated species from other Masses offered by the priest. The Church always has extra consecrated host (not wine) in the Tabernacle saved for the sick and in the event there are more in attendance at the specific Mass then the priest has consecrated. Because the species in the tabernacle is already the Body and Blood of Christ and in respect to what already" is" and what is "about to be" consecrated, the Eucharist (Blessed Sacrament) is covered and held in a secure place called the Tabernacle.
We genuflect in the presence of Jesus at the tabernacle, or before the sacred host when exposed, as Catholics believe this is the real presence of Jesus. Catholics bow in front of the altar, since it a consecrated sign of Jesus,but genuflect when Jesus is present there in the bread and wine, or at the tabernacle, where the body of Jesus in the form of bread is kept for distribution to the sick.
Consecrated Hosts are stored in a locked Tabernacle, not on the altar. The Tabernacle may be located immediately behind the main altar or on its own pedestal in the Church, non on the altar.
The red light near the tabernacle is typically called the sanctuary lamp or the eternal flame. It symbolizes the presence of the Blessed Sacrament reserved in the tabernacle and serves as a sign of Christ's presence in the Eucharist.
In Catholic churches the tabernacle contains the excess hosts consecrated at earlier Masses. Also, a 'luna' (large consecrated host) is held there so that Christ is always present, even if there are no excess hosts. The 'luna' is the host that is used for adoration and benediction.
In the tabernacle is the real presence of the glorified Jesus Christ, body and soul. While the accident of bread remains, the substance is completely different -it is the sacramental presence of Jesus
Hosts in the tabernacle are meant to be used for the next Masses and should not be left in the tabernacle for more than 2 weeks if possible, as they will tend to become stale but they still remain the body of Christ.