The Gifts tab allows you to open Clan chests that have been sent to you by your allies.

You can get a chest in any of the following ways:

1. Explore a crypt to 100% completion.
2. Defeat a heroic monster squad.
3. Get into the top 100 of any tournament.
4. Buy any package on the offers page.

Once a new chest has appeared in the Gifts tab, you only have 20 hours to open it. Otherwise, the chest will expire, and you will have to delete it.
Clan wealth is accumulated when members of the same Clan open gift chests.

Every 6h 30m, any player ranked Superior or higher can send all Clan members unique rewards in the form of wealth chests. The level of these chests depends on the current wealth of the Clan. However, the reward will not only include the chest for that particular level but also for all previous levels. 

If your Clan wealth reaches the maximum level,

your allies will get six chests — one of each quality level for each wealth level achieved.
To speed up any process in your city, you can ask other members of your Clan for help. Each time an ally helps, it speeds up the current process by 1% of the initial construction time. The amount of help requests available depends on your Capitol level. You can increase the amount of help that's available for particular processes using the unique research in the Academy, as well as Premium status: the Great Ruler title grants you five additional help requests for technology research and construction upgrades.

Each time an ally helps you, your Clan gains 100 help points. You can read more about Clan help and Clan borders here.
Both you and your clanmates can use each others' portals on the World Map, regardless of whether the portal was opened in your Kingdom or another one. The list of open portals is available to all players ranked Veteran or higher.

You can read more about portals and how they work here.
The Clan Announcement feature allows any player ranked Superior or higher to send a message to the Journals of all members of their Clan once every hour. You can also copy and paste event links or coordinates into your announcement. However, just so you know, the message cannot have more than 900 characters in it.
The Reinforcements tab allows any Clan member ranked Veteran or higher to view all their allies who have requested reinforcements and to send them troops as necessary. Please note that in order to be able to send or receive reinforcements, you first need to build a Consulate.
Raids are a special type of group march designed for attacking powerful enemies. The number of players who can take part in them is limited. They have a designated attack target and a deadline for rallying troops for the Raid. This mechanic is mainly used in the Rise of the Ancients and Ragnarök events.