Yes, x10Hosting has an inode limit (50000 for Free Hosting, even with unmetered storage; the various Premium plans have their own limits). An inode, or index node, can be roughly translated as "anything that a Unix-type operating system's file system can treat as a file", which includes both files and directories (which are just files that point to other files), email messages and so forth. Note that the size of the files doesn't come into play; using one big file instead of a thousand little ones means using one inode instead of a thousand. That means that if you are using things like tiny icons all over your site, using a "sprite sheet" or a graphical font will use far fewer inodes than storing a lot of small image files.
When you initially set up your account, though, you will also have a disk space limit (either 512MB or 1GB, depending on your account set-up). You may request to have that limit lifted later, but the potential for abuse and the low "cost" of sign-up for a new user (all you need to do is provide an email address) means that allowing a new user to flood the server with files has historically been a bad idea. There is a hard limit of 1GB, even with unmetered storage, for media files/galleries (photos, videos, etc.), and file storage/downloads are only permitted in very limited circumstances (see the Terms of Service for details); the space is provided for web sites, not for file sharing/distribution/cloud storage.