(The Supreme Bestower)
The One who is abundantly generous in giving without ever needing to calculate.
Allah is Al Wahhab (in Arabic: ٱلْوَهَّابُ), which means the great giver whose blessings are freely and perpetually given. He gives with no purpose and expects nothing in return. Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ is truly the most liberal giver, He gives to the deserving and undeserving, to the good and the evil.
From the root w-h-b which has the following classical Arabic connotations: to give for no compensation, to give as a gift to donate, to offer as a present, to bestow, or to give liberally and freely.
The name al-Wahhab speaks to Allah's nature of being the all endowering, all bestowing, or the perpetual giver of gifts. Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ loves His creation intimately, He gives without recompense or interests. In Surah Ibrahim verse 34, "And if you should count the favor of Allah, you could not enumerate them. Indeed, mankind is [generally] most unjust and ungrateful."
Give yourself a moment to reflect, look all around you, look at complexity of your body. We can not show enough appreciation to Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ for all of His blessings. The gift of life, how each cell everyday is at war, it wards off viruses and bacteria that want to destroy it. Yet here you are. Each cell performs its function in unison with all the other cells just so you can experience and be part of the universe. This is a gift from Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ.
"Do they possess the treasures of your Lord, the Most Mighty, the Great Bestower?" (38:9)
As mentioned before, when the names of Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ are paired it often conveys a greater message. In this case, the names al-Azeez (The Exalted / The Mighty) is paired with al-Wahhab. This signals the purity of the gift. Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ is all Mighty, he does not need anything, so when He gives, He gives freely. There is no ulterior motive, no looking to get in someone's favor. The pairing of these two names also shows how nothing can come in the way of His giving. We live in a world where politics, leadership, and logistics all come in the way, preventing good people from helping one another. The wealthiest countries in the world still have some degree of its population suffering from poverty and hunger, and it's not because of a lack of resources. Even if they wanted to help, they could not. Allah's bounties have no limits, and no one can prevent Him from Giving to whom He wills.
Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ does not need anything from his servants. We know His gifts are purely out of love. They serve as a reminder of His love for all His creations. He even gives to do those who might not be deserving, perhaps they would realize that it is their Lord who's showering them with blessings and that they return to Him.
How does a believer benefit from knowing al-Wahhab? We should learn use this name in our supplications just like the famous du'a of Prophet Suleiman (as) who recites this exact name of Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ asking for wealth.
"He said, 'My Lord, forgive me and grant me a kingdom such as will not belong to anyone after me. Indeed, You are the Bestower.'" (38:35)
We should also recognize any inherent talent we have, that it's a gift from Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ. We should remain humble servants and show gratitude for the blessings.
Narrated Uqba: I offered the Asr prayer behind the Prophet (ﷺ) at Medina. When he had finished the prayer with Taslim, he got up hurriedly and went out by crossing the rows of the people to one of the dwellings of his wives. The people got scared at his speed. The Prophet (ﷺ) came back and found the people surprised at his haste and said to them, "I remembered a piece of gold Lying in my house and I did not like it to divert my attention from Allah's worship, so I have ordered it to be distributed (in charity). 
Let's say you gave a gift to a friend, and you see it wasn't appreciated, used, or had the opposite effect you intended - how would you feel? The truth is it hurts. Imagine a recent kidney donor seeing their friend revert back to being an alcoholic. It would be a big slap in the face. Similarly, Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ has given certain people gifts that get abused. We have knowledgeable people, but they use their knowledge to manipulate and cheat others. In the act of omission, Allah's given some the faculty to achieve great things, but they don't live up to their potential. Instead, they waste their time playing meaningless games. We must try our best to use the gifts we've been given in a way that would insult the giver. We should share any gifts given and spread it to try and uplift others.
Just as Allah سُبْحَٰنَهُۥ وَتَعَٰلَىٰ gives gifts out of love we should learn to do the same. "Aishah narrated: 'The Prophet would accept gifts and he would give something in return.'" 
Abu Huraira reported that the Prophet ﷺ said, "Give gifts and you will love one another."  And just as a reminder, no gift is too small. Abu Hurairah (May Allah be pleased with him) reported: Messenger of Allah ﷺ said, "O Muslim women! No one of you should consider insignificant (a gift) to give to her neighbour even if it is (a gift of) the trotters of a sheep".