With over 1400 coins to pick from, how can you tell if one is worth investing in?  Lets start by looking at the top ten coins.

To help describe these coins, so that they can be compared as equally as possible, I have used symbols to represent some of the unchangeable aspects of a crypto.

Now that you know how the shorthand model works, lets look at each crypto individually.
I have given a short description of the reason the crypto was created in the first place, and what problem it is attempting to solve.  I also describe how the crypto is currently being used, which is not always in its initial intended way. 
Lastly, I look into its intrinsic value to investors.  In order for a crypto to have long term value, it requires a financial eco-system.  The eco-system requires interaction between the developers and the community who will ultimately use the crypto. This means there needs to be a way for the developers to earn income (so they can continue to develop), a way for the community to earn crypto (so the community has an incentive to be part of the project), a reason to spend the crypto, and an easy way for the crypto to be spent. If the crypto can't provide this eco-system then the crypto may struggle to survive long term.

CoinMarketCap.com is the go to site for most crypto enthusiasts.  Coin Market Cap maintains a comprehensive list of all the cryptos on the market.  But if you are new to trading, or cryptos, the terminology can be a bit daunting.

Let's look at each column and decipher what information each column is conveying:

#
This is the Rank of the coin.  Rank is determined by the Market Cap.  The higher the market cap, the higher the rank.  See Market Cap below.

Name
Obviously, this is the name the coin goes by, and is accompanied by its logo.
The name is also a link to a page with more details, links, and graphs for the coin (see below).

Volume(24h)
Volume is the trading volume in the previous 24 hour period.  This is calculated by adding all the buys and sells together that were filled in the previous 24 hour period.
The Volume(24h) is also a link to a list of the markets that list the coin (see above).

Circulating Supply
Circulating Supply is an approximate number of coins that are in the general public's hands.  By contrast the Total Supply is the total coins in existence currently and Max Supply is the approximate number of coins that will ever exist in the lifetime of the crypto.
The Circulating Supply is also a link to the block explorer for that coin.  

Now, let's look at the top of Coin Market Cap's website.  They have a very handy top bar, with additional market wide information.

Starting from left to right:

Cryptocurrencies
This is the number of cryptocurrencies currently on the market.
The link takes you to a list of all the cryptos, similar to the front page, but with slightly different details.

Markets
This is the number of market pairs available (BTC/ETH, BTC/USD, ETH/USD etc) across all markets.
The link takes you to a list of all the market pairings for each coin.

​Market Cap
This is the total Market Cap of all cryptocurrencies.
The link takes you the global charts for all cryptocurrencies.

​24h Vol
This is the trading volume in the previous 24 hour period of all cryptocurrencies. 
​The link also takes you the global charts for all cryptocurrencies (see above). 

BTC Dominance
This is the percentage of the total market cap bitcoin has.
​The link takes you to the Bitcoin Dominance Chart.

English/USD
This tab allows you to change the language and currency for the site.
​

The short answer is no.  The long answer is that cryptos are a little like plants.  They are all basically the same, but their specific features and goals can be very different, and the way we choose to use them can also vary widely.

There are three general categories of cryptos, Currencies; Platforms; Applications.

Currency Cryptos
These are the cryptos that we generally think about as being a cryptocurrency.  First and most notable of these is Bitcoin.​  There currencies are generally focused on replacing or working alongside an existing currency.    These cryptos use their blockchain to keep track of who owns what coin. 
These cryptos can also be considered a Storage of Value as it is asserted that as the number of coins is limited, and as the demand for coins grows, that the value of those coins will increase. 

Platform Cryptos
These cryptos are built in an operating system style network.  This allows other applications to be built using the platform as a base, but while being independent themselves.  Applications that are built to operate on a particular platform are called D'Apps (Decentralised Apps).  The most notable of these platforms is Ethereum.  Platform cryptos have their own type of currency, that is used to buy & sell the use of the platform.  These currencies can be bought and sold as you do other currencies, but they are intended only to pay for use of the platforms network.

Application Cryptos
D'Apps (Application cryptos) perform a specific function, like traditional software does, but on the internet, on a webpage.   Think of all the cloud products you use today such as Facebook, DropBox, Gmail,  TradeMe, Youtube, or any app you run on your computer of phone.  All of these will, in time, be replicated in a D'App form.  They will look similar on your screen, but in the background they will be infinitely more powerful.  In reality this should lead to less expensive and more secure applications for you to use in your everyday life.
To confuse things a little, D'Apps can also reply on a platform to perform the back-end functions, or it can be a standalone application, that features its own blockchain.

That all sounds easy and straightforward, right?

Well, not so fast.  Its a little more complicated, and the divisions between each of these types are actually not that well defined.  In fact, many cryptos are a little of one and a little of another, or all three!  To make things worse, as this is still a very young and very fast emerging industry, definitions are still up for debate, and even when there is some agreement, that agreement can change when new technologies emerge.  As there are new techniques, and new technologies appearing in the market every day, new types are added, and debate rages as to whether a technology fits in one place or another, or whether it is a new categories all of its own.

Let's think about some examples.
Currency Cryptos
Bitcoin (BTC)  - This is the most famous crypto currency, and its intention is to be a currency that replaces the use of traditional currencies.
Monero (XMR) - This is designed to be a replacement currency, and focuses on anonymity as its main feature.
Ripple (XRP) - This is designed to be a currency system focusing on transferring value between banks globally. 

Platform Cryptos
Ethereum (ETH) - Ethereums' main purpose is to be a platform on which applications will run, and the token (currency) is to be used to buy and sell use of the platform.  However, Ethereum is currently also used for real-world transactions, that do not include use of the platform, other than to process the transaction itself.  
Lisk (LSK) - Lisk is designed for applications to be built using Lisks' blockchain for the backend, and focuses on allowing the use of currently available programming languages.

Application Cryptos
Golem (GNT) - Golem is one of the first D'Apps built on Ethereum.  Golem focuses on using unused global computing power to power a "super-computer" that can be used for CGI rendering, or scientific calculations for example.
Siacoin (SC) - Siacoin focuses on large scale data storage, but features its own blockchain.


So, no, cryptos are not just currencies, they are so much more.  The reality is that we have barely scratched the surface of what cryptos can do.