You might have seen Vishnu's picture with four things carrying in His hands - lotus flower, Chakra or discus, Gadaa or mace, and Shankh or conch. His this Moorti (figure) is for blessings, as well as for protection. Lotus is to bless the people as it shows that He is very soft-hearted, Shankh is to frighten the enemies thus soothes the Bhakt, and Gadaa and Chakra are to protect His Bhakt. He has two weapons more which He takes up occasionally according to the situation - they are a sword and a bow. All have their own names. Today I will write about these weapons as what are their names, where did he get them and their some uses He made.
Krishn's conch's name is Paanchjanya. He got this conch after killing a Raakashas named Panchjan who lived in the sea in the form of a conch. He went to get educated to Saandeepan Muni. When He and Balaraam had finished their education, according to those times, He asked His Guru as what Guru Dakshinaa He should pay. Guru Jee knew who Krishn was so he did not ask anything from Him. He just said - "I am blessed to receive you as my disciple, that is all, I do not need anything." But Krishn insisted that His education was not complete unless He had paid His Guru Dakshinaa. So Guru Jee directed Him to his wife saying that He could ask His Guru Maataa if she needed anything. So Krishn and Balaraam went to to their Guru Maataa.
Now Guru Jee had a son who died long time ago. Guru Jee knew this but Guru Maataa was not yest convinced. She thought that he was lost in a fair, while in reality he had died in the sea after drowning. So when Krishn asked His Guru Maataa if there is anything she needed anything for Guru Dakshinaa, she asked Him to search for her son. Krishn went to the sea and asked him to tell about His Guru's son. Sea said - "I have not taken your Guru's son, but there is a Raakshas named Panchjan living in me in the conch form, you can check there if he has taken him. So Krishn went there and killed Panchjan, but He could not find Guru's son there. When He had killed that Raakshas He brought his body with Him. The same Raakshas' body, in the form of conch, is now Krishn's conch Paanchjanya. That is how Krishn got His Paanchjanya Shankh. When He used to blow His conch the enemies used to get frightened.
Raam's brother Shatrughn was the incarnation of His Shankh.
Krishn's Chakra's name is Sudarshan. It has 1,000 Arey (spikes) inside and its speed is very fast. Nobody can escape from His Discus. After doing the assigned work to it, it comes back automatically to Vishnu. How Vishnu got His Chakra, is an interesting story. When Soorya Dev got married to the daughter of Vishwakarmaa, named Sanjanaa. Sanjanaa lived with him for some time, but she could not live with him for long, so Vishwakarmaa put Soorya Dev on his lathe and cut 1/8th part of his powers. The fragments that fell on the Earth because of this operation were used by him to make Sudarshan Chakra for Vishnu and some other weapons for other Devtaa. According to Mahaabhaarat, when Agni Dev asked Arjun to satisfy him with food, Arjun said - "I don't have proper means to fulfill your wish. If you can arrange me the means, I can give you food." So Agni Dev went to Varun Dev and brought some things from him - chariot, inexhaustible quiver, Gaandeev bow for Arjun and a Disc and a Gadaa (mace) for Krishn. Then only Arjun and Krishn could burn Khaandav Forest and satisfy Agni Dev.
(1) First Krishn used His Chakra to kill Shishupaal, and and then to kill fake Krishn. Krishn Himself told a story to Arjun about His Discus. He said - "Once Jayadrath came to Dwaarakaa and expressed his desire that he wanted to be very mighty like me. He knew that my Discus does not go empty and that is what he wanted from me, so he asked me my Discus. First I politely ignored his request, but when he did not listen to me, then I gave it to him and asked him to hold it, but it was so heavy that he could not hold it, so he abandoned the idea to have it and said - "Krishn, It looks good in your hands only." and went away.
(2) Vishnu has used His chakra to cut the neck of Raahu Daitya also at the time of Saagar Manthan. This gave birth to Daitya - Raahu (the head) and the Ketu (the tail),
Raam's brother Bharat was the incarnation of this Sudarshan Chakra.
It is believed that Kaartveerya Arjun (Sahastrabaahu) was the Avataar (incarnation) of Vishnu's Sudarshan Chakra. As the Chakra had 1,000 spikes, he also had 1,000 arms.
His mace's name is Kaumodakee. When Arjun pleased Agni Dev by burning Khaandav Forest, he gave Krishn and Arjun several things. One of them was this Kaumodakee Gadaa which he gave to Krishn. Krishn used His Gadaa to fight wiht Kaalayavan Raakshas after he had killed most of his army by His Shaarng bow.
Krishn has a bow also, Its name is Shaarng. He killed most of Kaalayavan's army with His this bow. And then He fought with him with His Gadaa Kaumodakee.
Krish has a sword also. Its name is Nandakee.
Krishn's chariot is very special. Its name is Jaitra (Vishnu Puraan, 5/14). He has another chariot too which is named as Sugreev Pushpak. His chariots are driven by His special charioteer named Daaruk. His chariot is drawn by four horses - Sugreev, Meghpushp, Shaivya and Balaahak. These horses run with the speed of wind. His chariot was equipped with all kinds of His weapons which He might need at any time.
Apparels and Other Identification Marks of Vishnu
His apparels include
--a peacock feather worn as His crown (Mor Pankh)
--a flute (Baansuree)
--earrings of a fish shape (Makaraakrit Kundal)
--yellow cloth worn on the upper part of His body (Peetaambar)
--a Vaijantee Maalaa or Van Maalaa on His chest
-- a cow on which Krishn leans on (Gaaya)
These are Krishn's weapons, chariots, driver, apparels etc etc.