Its primary use is to represent the player's personal hub. The secondary use is to track the player's game statistics, to showcase game achievements and player's champions roster. It also has several customizable esthetics features to better visually distinguish a player amidst other League of Legends players (for example: profile banners, frames, and summoner icons), and bonus pre-game customizable features which use is to enhance player's champion stats and also to add different bonus abilities before each match. These bonuses fall into three categories: summoner spells, runes, and masteries.
In order to access certain information, you must be friends with the summoner, but certain information, such as their rune pages and mastery pages, are open for all to see.
The profile is separated into different tabs.
The Overview tab shows the current summoner level, currently activated experience boosts, ARAM rerolls, and the number of available Hextech Crafting chests obtainable. In the "Overview" tab you can also see your current Honor level for this season, your most mastered champion, and your current rank in ranked games (which are only available from summoner level 30).
The Match History tab shows your last 20 played matches, with, eventually, the option to download a Replay the game, so you can watch it again. This tab also shows some stats, based on the last 20 played matches: your 3 most played champion, and what type of champion you most play.
The Ranked tab, is only available after level 30 and shows your league information.
The Clubs tab shows information about the clubs you're in, like who's the Owner, Officer or Member of the club, and when they joined the club.
The Highlights tab shows all the Highlights you made by pressing the red button while in a Replay. You can watch the Highlight while in the client or directly from your computer, by clicking on the "Show Highlight in file browser" button, and the playing the .webm file.
A summoner icon is a picture that represents a player. Players are initially given a set of 29 icons to choose from, this number can get large depending on the player's actions. Other icons are accessed by purchases in the Riot Store, completing Missions during specific events or achieving the corresponding rank in different ranked queues.